What Is a bad sector and how can I repair it?

By Liz Cornwell | February 11, 2010 |

greater than 3 minutes

Bad sectors are little clusters of data on your hard disk that cannot be read. More than that, though, they are the potential to cause real damage to your hard drive (catastrophic failure) if they build up over time, stressing your read arm. Bad sectors are fairly common with normal computer use and the imperfections of the world we live in; however, there are several simple steps you can take to prevent HDD bad sectors and to repair any that you do have. Having bad sectors will not speed up computer performance as well. Here is a step-by-step guide.
What is a sector, and how are HDD bad sectors created?

A sector is simply a unit of information stored on your hard disk. Rather than being a soupy mass of fluid information, your hard disk stores things neatly into “sectors”. The standard sector size is 512 bytes.

There are various problems that can cause HDD bad sectors:

  • Improper shutdown of Windows;
  • Defects of the hard disk, including general surface wear, pollution of the air inside the unit, or the head touching the surface of the disk;
  • Other poor quality or aging hardware, including a bad processor fan, dodgy data cables, an overheated hard drive;
  • Malware.

Hard and soft bad sectors

There are two types of bad sectors – hard and soft.

Hard bad sectors are the ones that are physically damaged (that can happen because of a head crash), or in a fixed magnetic state. If your computer is bumped while the hard disk is writing data, is exposed to extreme heat, or simply has a faulty mechanical part that is allowing the head to contact the disk surface, a “hard bad sector” might be created. Hard bad sectors cannot be repaired, but they can be prevented.

Soft bad sectors occur when an error correction code (ECC) found in the sector does not match the content of the sector. A soft bad sector is sometimes explained as the “hard drive formatting wearing out” – they are logical errors, not the physical ones. These are repairable by overwriting everything on the disk with zeros.
How to repair bad sectors

Windows has inbuilt check disk tool, called “Chkdsk”. It is recommended to run this tool from time to time. It will scan the disk for errors, fix logical errors, detect and mark bad sectors, so that Windows will no longer try to use them. This way it can prevent your computer from becoming unstable.

There is a slight disadvantage, though – Check Disk may require a lot of time to perform its task. It depends on many things, like overall PC speed, number of files and folders on the disk, amount of RAM, and disk size. So it’s best to run Check Disk only if you don’t need to use the computer for some time.

Also Windows Chkdsk wants exclusive access to the computer. In most cases it will ask for a reboot and will run right after the reboot, so you won’t have access to your PC. Of course, you can always interrupt the process, but it’s not a good idea.


To run Check Disk do this:

  • Find the My Computer icon on your desktop and double-click it;
  • Find the disk you want to check, right-click it and go to Properties;
  • In the Properties dialog box go to Tools;
  • Click Check now;
  • A new dialog box will appear, check both options and click Start;
  • Most likely you will get a message that Check Disk wants exclusive access to the disk and wants to start right after your reboot. Click OK;
  • Restart your computer.

Preventing bad sectors

You can help prevent bad sectors (always better than trying to repair them!) by paying attention to both the hardware and the software on your computer.

Preventing bad sectors caused by hardware

  • Make sure your computer is kept cool and dust free;
  • Make sure you buy good quality hardware from respected brands;
  • Always move your computer carefully;
  • Keep your data cables as short as possible;
  • Always shut down your computer correctly – use an uninterrupted power supply if your house is prone to blackouts.

Preventing bad sectors using software

  • Use a quality disk defragmenter program with automated scheduling to help prevent head crashes (head crashes can create hard bad sectors). Disk defragmentation reduces hard drive wear and tear, thus prolonging its lifetime and preventing bad sectors;
  • Run a quality anti-virus and anti-malware software and keep the programs updated.


Are you running out of ideas on how to speed up your computer? Read our next article to learn more about slow computer optimization and tricks that make computer run faster and smoother.

Share it:
Do you like this post?
1 Star2 Stars3 Stars4 Stars5 Stars (3 votes, average: 2.33 out of 5)


  • D
    Dani Kisser
    November 29, 2011 @09:11 pm

    Thank You buddyy Its reallly work:)

  • K
    December 13, 2011 @08:44 pm

    Thanks dear for your informative article.

  • P
    December 22, 2011 @07:45 am

    ummm…. how exactly does defragmenting a disk on a schedule prevent hard bad sectors? i could be over looking something, but defragmenting basically moves data to be “congruous” (all in a row) so that its quick and easy to access, it will help decrease seek times etc, but preventing a hardware issue it does not. I guess it could help cut down on disc wear etc, and keep the head from being in use in times where its likely to get bumped, but that should be explained, not left for the user to guess?

  • L
    January 16, 2012 @02:37 am

    Defragmenting will reduce and/or help prevent “soft bad sectors” , not “hard bad sectors”. Think of it as virtual corruption versus actual physical corruption. Like if you scribble on paper with pencil you can still erase it – (soft). Crumple and tear the paper, and you have to replace it – (hard).
    When the computer is unable to read a part of your disk during Chkdsk, it may mark it as a “bad sector” because it is unreadable or corrupted from a virus, but still repairable.
    Repairing the file area with an anti-virus and putting it back into a healthy, fast working order can free it from a status of being labeled as a “bad sector”.
    If you have been lucky enough to repair bad sectors in this way you can free them up by doing another Chkdsk.
    This time, use Cmd by clicking:
    Start > Type Cmd > Right Click and choose Run as administrator
    Next, type: Chkdsk /b
    and hit Enter
    (note the space between the “Chkdsk” and the “/b”)
    This will perform another scan to check the files to see if they are actually bad (physically damaged) OR if they have been repaired. You can do this after getting rid of viruses and other malware, getting rid of junk files, defragging and getting everything else in working, clean order.
    It takes about the same length of time to do this Chkdsk, so I do mine before bed and check the log in the morning. (Windows 7 Chkdsk log is located at C:\System Volume Information\Chkdsk
    (if “C:” is the name of your disk you scanned).
    But don’t hold your breath. Bad sectors is never a good sign, and more often than not, it is unable to be repaired.

  • J
    April 4, 2012 @10:16 pm

    Thank you bro!!!
    for information about bad sector

  • A
    June 8, 2012 @04:43 pm

    Thank you for sharing this knowledge. Helped me tons.

  • T
    June 13, 2012 @03:59 pm

    Excellent article, I have some old PCs that i’ve neglected for a while so i’m gonna perform a Low Level format on them to clear the errors they’ve built up. So far, I’ve downloaded the tools from Seagate, hopefully it will make my old drive last longer… but first I need to make a backup! lol i’ve been using CCleaner to clear the Free Space, but I don’t know if that made any improvement to the drive.

  • S
    June 26, 2012 @08:56 am

    I have heard that bad sector can be repaired by formatting with windows 98. Is it true

  • P
    July 9, 2012 @11:35 am

    I know a software called PBD(Partition Bad Disk) can isolate the bad sectors and create healthy partitions automatically.

  • S
    sudesh patil
    July 21, 2012 @07:57 am

    Hello sir
    My computer is getting problem there is bad sector problem. I was format my PCs C drive and when i restart copying the files of os that time it doesnt copy the file, there is a automatically comes a dark blue window and stop the next copying proces.what exct problem ? and also giving the error code 0x80070570 this. how can i solve this problem? do u have any solution for that? please help me.

  • N
    No Love
    September 14, 2012 @08:00 am

    Thank you bro!!!
    for information about bad sector

  • N
    naresh sahu
    September 25, 2012 @10:59 am

    Hello sir
    My computer is getting problem there i boot system succfully one time but i restart or shut down they they does not boot and show errors disk problem
    then i repairs winxp with cd system run succ. one time but i restart or shut down they they does not boot and show errors disk problem again and again
    plz. solution

  • D
    September 26, 2012 @11:50 am

    please help me some time and send me new idea problem solving

  • P
    September 29, 2012 @04:57 pm

    ive got a sony vaio n it boots in safe mode without any issues but fails to do so in normal mode. Sony service center informs its a bad sector n d hard disk needs to b replaced since recovery wont help. However my laptop gave me ‘No operating system found’ error quite a few times.
    Can u tell me whether the hard disk really needs to b replaced or is d service center just trying to cash in on this opportunity???

  • D
    October 8, 2012 @07:14 pm

    file are copy to other HDD

  • M
    October 8, 2012 @08:22 pm

    My computer is getting problem there is bad sector problem. I was format my PCs C drive and when i restart copying the files of os that time copy is going with slow speed,it takes long time and not gives any other message…what should i do????

  • A
    October 16, 2012 @06:38 am

    Thanks heaps! This helped me during my time at workplacement 😀

  • R
    Rana Ubaid Ali Najmi
    October 19, 2012 @03:53 pm

    thank you for information.

  • O
    October 24, 2012 @02:50 pm


    It workd well with command chkdsk “/D”

    but the bad sector area apear again while chekc with chkdsk “D”


  • T
    October 30, 2012 @01:50 am

    My comp won’t boot up, it says my hard disk needs to be replaced? Not sure what that means? Is there anyway to get ariund this so I can boot up my comp so I can fix the problem?

  • C
    November 2, 2012 @10:24 pm

    its true man. you need to replace your hard drive. i had that exact same problem. note they will just you double the price to install the thing as well. i just bought the hdd on its own. simply a matter of unscrewing it. taking it out being careful only to handle the sides if you can then take it out and slap the new one in.
    keep your old hard drive. you could look into freezing it later on. you put the hdd in two plastic zip lock lunch bags and stick it in the freezer. after a day or 2 take it out and put it in a computer and if it works then recover what was lost quickly. you can only do this once i think but im not sure.

  • R
    November 3, 2012 @06:11 pm

    i m unable to run my pc till dektop menus because thier bad cluster in hdd are in large amount.so give my any soltution to block bad sectors or remove them…if any possible solution is here ..then tell me soon???ur suggestion is more useful for me on thease days ..soo plzz help me:)

  • S
    November 4, 2012 @07:53 am

    I’v a lenevo laptop ,& while i’m trying to re-install windows xp in it,a blue screen is appearing,showing a msg,”A problem has occoured,cann’t install xp in this computer.” I’ve tried various setups,results are same. Is it a bad sector prblm? I’ve tried ur procedure,no progress.Plz,help me..!!

  • A
    Anna Lind
    November 6, 2012 @08:43 am

    I am sorry, but there are just too many things that could be the reason for this problem. I would recommend contacting a local technician for assistance.

  • S
    syed jahangir
    November 16, 2012 @10:59 am

    My hp pavillion gv6 laptop , i guess , due to an abnormal start , stopped working. I was busy , so didn’t take a note . I left my laptop as such . Now that i tried reinstalling windows 7 using a cd or a bootable pendrive, it allows me to choose language , keyboard layout etc .when i click next , what it displays is ” Set up starting ” with the cursor arrow showing processor busy sign , and then goes on as such .Even if u leave it as such for a whole night , the screen would still show the same thing. Some friend of mine told me that it is a hard disk bad sector error and that the hard disk needs to be changed . What do i do now …..please please please help me out 🙁 ??

  • R
    November 24, 2012 @08:25 am

    I like you.

  • E
    December 10, 2012 @01:53 am

    very good for primary level computer user…!!!
    I think we should discuss about physical bad sector and how do we repair it…!!!!

    Hope honorary admin respect my comment…!!!


  • -
    December 20, 2012 @09:14 pm

    thanks for all the tips and great article!
    my 2 tb is failing bad.. thanks to your article i now know for sure its because my cpu fan was having problems and causing improper shutdowns. but are these bad sectors hard or soft? hdd sentinel says its now at 3% health.

  • -
    December 20, 2012 @09:18 pm

    can you explain to me how much of this is physical? what it all means exactly?
    “There are 72 bad sectors on the disk surface. The contents of these sectors were moved to the spare area.
    The drive found 348 bad sectors during its self test.
    There are 348 weak sectors found on the disk surface. They may be remapped any time in the later use of the disk.
    9192 errors occured during data transfer. This may indicate problem of the device or with data/power cables. It is recommended to examine and replace the cables if possible.
    At this point, warranty replacement of the disk is not yet possible, only if the health drops further.
    Problems occurred between the communication of the disk and the host 929 times.
    It is recommended to examine the log of the disk regularly. All new problems found will be logged there.”

  • -
    December 20, 2012 @09:21 pm

    i replaced cables.. like i said improper shutdowns.. how bad is it physically exactly?

  • -
    December 20, 2012 @09:24 pm

    one last thing.. the power on time is only 210 days.. will just formatting it fix most problems? thanks

  • A
    Andre James Anderson
    December 27, 2012 @11:35 pm

    The info in this article is incorrect in several fundamental ways.

    Most importantly, there’s no such thing as a ‘soft’ or ‘logical’ bad sector, sadly. All bad sectors are, by definition of that term, ‘hard’ or hardware-level issues. They can be discovered by reply utilities such as CHKDSK whose “surface scan” option writes to each sector and then reads back to verify integrity. If a problem is detected, the sector is marked ‘bad’ and henceforth avoided by the file system.

    Because of the above, improper shutdowns of the OS will not and cannot cause bad sectors. That’s a misunderstanding on the article author’s part.

  • M
    Manish Sharma
    January 8, 2013 @06:11 pm

    Friends, if your system doesn’t starts nicely and displays errors like ”Error Disk Problem” ”No boot media found”
    thn Replace a new sata cable for Hard disk and if problem persist change the power cable of Hard disk. This would surely do the needful. I had this problem and also Dvd drive failure, Corrupted Windows.
    I’ve cured the above three problems with the mentioned procedure. 🙂

  • S
    January 12, 2013 @05:35 pm

    Thank you bro!!!
    for information about bad sector

  • A
    January 13, 2013 @02:25 am

    it is true that defragmenting tools help the computer to be faster because data can be all in row, and of course this methode can halp to protect the hard drive.
    head crash can caused from touching the surface of the Hard disk , and if the head moving all the time to read or write data from different rows because the data which is needed not in the same row, then this can cause more heating and also not really stable moving.., specially in new hard disk the place between the head and surface is very small, and air is important inside to let the head fly over the surface, moving the head all the time to different rows can some times not be stable… in this case head crash can ocure. it is rarely to say that this is the reason of headcrash but it is possible to occure

  • F
    January 18, 2013 @05:48 pm

    Hi, I have a 500 GB with 266 bad sectors… How serious can this be?

  • S
    Shan AHmed
    February 19, 2013 @12:14 am

    HI Dear

  • V
    Vandit Dholakia
    March 7, 2013 @01:52 pm

    I have Segate 1 TB External Hard Disk.
    One day, it was getting detected & undetected automatically. From the next day, it is not getting detected in the system. Then, using SeaTools I tried to check for errors in which it shows Bad Sectors due to virus. I have heard this for the first time that a bad sector may occur due to virus. Can it happen? And how can I repair my Bad Sectors so that the hard disk gets detected again? Please help me out. Thank you.

  • U
    March 19, 2013 @11:42 am

    HI Dear

  • P
    Pablo Zacheo
    March 21, 2013 @01:59 pm

    >Hard bad sectors cannot be repaired, but they can be prevented.
    Sorry to correct this part of your article, but they can be repaired.

    In fact I’ve been doing this for long thanks to a russian software made by Dmitriy Promochenko called HDD Regenerator.

    This is the only software that can not only repair a heavily damaged hard drive but it will also recover entirely the data, not only repairs the bad sector it will also restore its information.

  • J
    March 31, 2013 @01:20 pm

    for information…..

  • R
    April 5, 2013 @03:01 pm

    Hello sir
    My computer is getting problem there is bad sector problem. I was format my PCs C drive and when i restart copying the files of os that time it doesnt copy the file, there is a automatically comes a dark blue window and stop the next copying proces.what exct problem ? and also giving the error code 0x80070570 this. how can i solve this problem? do u have any solution for that? please help me.

  • M
    mohamed sahir
    April 5, 2013 @10:19 pm

    hello sir,am sahir, i am using hp laptop.. oneday it will shut down forcely.. after that the hardisk wont boot up.. it only shows the hp bios page..but the hardisk is detect and show the datas when i use it as external one.. its a badsector problem.. its doesnt boot.. how i getting overfrom that problem..
    if you can help me, plz give the idea

  • T
    tera papa
    April 11, 2013 @10:51 am

    sudesh patil,

    its call blue dump…….remove the ram and inject the other slot properly and than reinstall the window.

  • R
    April 13, 2013 @10:25 am

    its call blue dump…….remove the ram and inject the other slot properly and than re install the window.

  • K
    April 16, 2013 @09:06 pm

    Very informative and helpful. Thanks

  • B
    April 17, 2013 @09:53 am

    Nice article. Well explained.

  • E
    April 18, 2013 @11:39 pm

    physical bad sector is unrepairable. to safe hdd we do full format, then we take 3 partition one reserved for bad sector and other two is usable..!!


  • O
    April 23, 2013 @07:59 am

    “I’v a lenevo laptop ,& while i’m trying to re-install windows xp in it,a blue screen is appearing,showing a msg,”A problem has occoured,cann’t install xp in this computer.” I’ve tried various setups,results are same. Is it a bad sector prblm? I’ve tried ur procedure,no progress.Plz,help me..!!”
    I Don’t think so. There are many problem, the blue screen my be cause by your hardware, examble your ram or the harddisk mode.
    You can swap to IDE mode and try to install again.
    Good luck!

  • B
    April 27, 2013 @07:55 pm

    First of all i would like to thank you people who hard given these information because i benefited alot out of these information’s and truly they had helped me. and once again i thank you every one of you who has given us this knowledge.

  • R
    Rashidul mUMENIN
    May 2, 2013 @11:06 am

    Dear Sir, How can I solve Hard Disk Bad sector

  • R
    May 6, 2013 @08:03 am

    i have a bad sector in c:\ pls help me to remove or repair the sector how can i repair or remove it pls give me advice is there a software available to repair it pls name to me on my email address thanks i have 1 tb hard drive windows xp

  • J
    May 26, 2013 @02:47 pm

    in xp type cmd.exe in start/run
    then type chkdsk/f
    thats it

    can you boot?otherwise this doesnt work

  • N
    Nikunj Shukla
    May 27, 2013 @06:08 pm

    I got Hard bad sector in my internal harddisk. its about 80-90 GB portion I can’t access. Is there any way so That part of disk doesn’t displayed and can’t be accessed. I mean to say I can’t attempt for accessing that part.

  • P
    June 21, 2013 @11:58 pm

    Thanks for useful info

  • T
    Thomas DeHart
    June 23, 2013 @12:31 pm

    I used Auslogic Registry Cleaner and did the undoing demize of taking out COM/ActiveX reg keys when cleaning the hard drive registry. I then went on to defrag and this is when I noticed that there was a “bad health” showing on the defrag. I then, commensed to starting a chkdsk -r and this is when the command got to the 144168 file and froze. I now cannot boot my computer and I tried using the free recovery disk from Acer/Emachines and the disk works up to the point of recovering the hard drive. All of the options are greyed out and unrespondant to choices of going back to a factory restore. My question: will a full restore/recovery disk from the manufacturer fix this problem? Thanks for the input. Cheers to all.

  • J
    June 29, 2013 @12:33 pm

    parag, hello there i have got this solution about ur hard drive i think u shud formate ur disk drive and delete ur all data and u will get it back

  • R
    July 11, 2013 @06:37 pm

    What to do when you plug in your pendrive in to the computer and prompts you to format it first before you can use it again?

  • A
    July 19, 2013 @09:46 pm

    Thanks for your info.Even after performaning thorough format my hard disk ,it rans into cyclic data redency check error(usually first partion).Is it a hard bad sector? Should i change my hard disk? Will it spread?

  • M
    m basiq bin nadeem
    July 23, 2013 @09:07 pm

    its so use ful

  • M
    Mohammad wali
    July 24, 2013 @06:05 am

    but the bad sector is not remove physically on the hard disk after checking the hard disk drive don’t show the actual or perfect reading.
    so how can we remove bad sector physically or logically?

  • R
    July 25, 2013 @11:46 am

    hi there! just want to ask if having my hard drive initialize the checking and choosing attempt recovery of bad sectors will it bring back the corrupted files that’s store on my hard drive ? thank you ..

  • J
    John Reid
    August 5, 2013 @12:37 pm

    If you have bad sectors in your hard disk, running a program such as Microsoft CHKDSK or ScanDisk and performing excessive attempts to read the disk can make matters worse. Your best chance of successful recovery of your data is to take your drive to a data recovery specialist and allow them to examine the disk.

  • A
    August 6, 2013 @12:38 pm

    this is good sach im using this tools

  • S
    August 6, 2013 @10:50 pm

    hi, i hav a problm in my sony vaio laptop, last tym when i was using my laptop,it automaticaly hangs up,and my lapi is givn error msg tht is “Operating System is missing” , after tht i restarted my lapi but it stuck on windows 8 loading screen.I thought there mst be problem in operating system,i tryed to install windows 8 again on my lapi,but installation is always stuck on loading screen i.e “Setup is Starting” screen.i am confusd , i dnt knw wht to do next.my friend told me tht my lapi’s hdd is having bad sector problem,how to resolve this problem,plz help

  • I
    August 6, 2013 @11:33 pm

    can u help me to repair bad sector 303, 301 and 305…..im using i3 (hp pavilion dv6)

  • S
    August 17, 2013 @02:25 pm

    i have a IDE HDD with 1Gbyte capacity i am working with DOS & i have some problem with bad sector . how can i repair bad sector ?

  • J
    John Raymond
    August 17, 2013 @11:40 pm

    Thanks for the good article. Unlike many on the net, it is honest. People are always claiming to be able to fix bad sectors (and I’d have to agree with the guy who said that “bad” usually means “physical” to almost all PC techs and not some file system or partition error) and there are still plenty of kooks that believe that the “HDD Regenerator” (and others) can fix damaged surfaces. The explanation offered was even more ridiculous, implying some magical, vibrating magnetic fields were used. Fixing the disk with a program is like trying to program a pothole in the street to be filled – it ain’t going to happen.

    I have had power surges cause bad sectors on a drive, too. They usually differ from the most common by not increasing in number over time, the sure sign that the drive is dying and needs to be replaced. If the number does not increase, partitioning around the bad area works well.

  • J
    John Raymond, Microsoft MVP
    August 17, 2013 @11:50 pm

    Pablo Zacheo,
    Not going to happen. That junk software only unmarks the clusters so that they look normal to the system. If they are readable, the data is then accessible. That can happen at times, sometimes due to simple factors like temperature.

    But the program does not “fix” anything, the areas are still unable to reliably hold data, and relying on them will lead to heartache. It would be irresponsible to assure a user that a drive that was “repaired” with that program or that the drive was all right to use for sensitive data.

  • T
    August 24, 2013 @06:05 pm

    i can’t use safe mode as well as normal window start up in my laptop. it shows Boot Configuration Data(BCD) atore file contains some invalid information.

    but i have lot of my personnel information in my laptop. i need it . what can i do to solve the problem and make my laptop function properly.

    please give some steps to over come that problem. i lost my os cd also. so say other idea to solve it with out using the os cd

  • U
    September 22, 2013 @01:13 pm

    is deleting and recreating the partition will help fix the bad sectors?

  • S
    Sanjib Chatterjee
    October 17, 2013 @12:40 pm

    I have 160 gb hdd with 4 partitions. In partition c when i check for error I found that i have 8 kb bad sectors in the c: drive. All other partition have no error. I have followed the process. Everything is working fine but when i check for effor it is showing that error.

    Is it a matter of regret for the little amount of bad sectors?

  • A
    October 24, 2013 @05:10 pm

    such a nice information thankyou very much

  • M
    Mohammad Abedi
    October 25, 2013 @12:07 pm

    Is there any way to repair hard bad sectors?

  • I
    Ishant Raj
    January 7, 2014 @09:14 am

    I format my System. while reinstall again there a problem of
    boot manager is missing
    bad sector in hard disk
    window cannot be install on GPT Drive
    i Don’t have any OS in my laptop currently

    I need help Urgently

  • S
    March 24, 2014 @09:59 am

    It is fantastic I learned much better Thanks

  • N
    May 1, 2014 @04:48 am

    You did a good job. Because i had facing these problem. So i got my conclusion..

  • Z
    May 29, 2014 @07:20 am

    i want my hard drive compute

  • R
    June 22, 2014 @01:16 pm

    Thank You very much.

  • T
    November 5, 2014 @05:04 pm

    my problem is my 500 gb hdd showing in win 7 disk management only without any size and health with 13 mb unlocated drive with 7 partitions when i joint as external hdd with my pc ,this hdd. my computer is going hang and i not do any work with this . in time hang i am not do format and doing nothing with any recovery software. just hang and after unjoind the external hdd msg appear format all partition but not format after pushing button yes

  • A
    Anonymous Admin
    December 16, 2014 @07:30 am

    Thankz Dude

  • N
    Nius Tan
    December 31, 2014 @07:52 am

    Thanks man…

  • S
    Siddhant Choudhary
    May 4, 2015 @12:17 pm

    Sir I have given my PC to a repair shop for fully formating the PC and installing a new windows.
    My PC was working before that and when I bring it back from shop the problems occurs about starting up the PC. It is not starting.
    The man of that shop told me that it is about bad sectors in HDD .
    What is the solution for that.