Unlike previous Windows versions, Windows 7, 8, and 10 come integrated with Windows Search, a powerful search functionality that helps you access files and folders on your PC faster. To access the Windows Search function, simply press the Windows logo key on your keyboard or click “Start” and start typing. Alternatively, you can use the Win + S shortcut.

Occasionally, the Windows Search feature may fail to initialize. As a result, the system takes much longer to find your file or folder. According to some users, indexing is responsible for causing slow system performance. But does indexing really affect Search in Windows 10? In this post, you’ll find everything you need to know about search indexing, including what it does, why it’s always running in the background, and the types of files that can be indexed.

What Is Search Indexing in Windows 10?

If you open the Control Panel, you’ll see “Indexing Options”. These options allow you to adjust how Windows Search works. The SearchIndexer.exe process is responsible for managing the indexing of your files for Windows Search.

But what is search indexing, and what are its functions?

In Windows operating systems, search indexing is the process of inspecting files, folders, data stores (such as Outlook mailboxes and system folders), and media and other types of content on your PC and cataloging their information, such as their metadata and words in them. So, the next time you perform a search on your Windows PC, Windows will look at the already created index of terms to give you results faster.

The first time you initiate the indexing process, it might take a few hours to complete depending on the size of the files. However, once it’s done, indexing runs in the background as you use your PC and only re-indexes the updated data.

What Is Search Indexing Used For?

An index, just like in books, helps a user access specific information faster. The Windows OS uses the digital index to quickly find content on your PC. Since all the information is already stored in a database, indexing allows your PC to look for common terms or properties, such as the date a particular file was created or renamed.

When you enter a search query – for instance, “Music” (assuming you have a folder labeled “Music”) – the system returns the results 10 times faster compared to searching without an index.

What Types of Files Are Indexed?

Now that you have an idea of what search indexing is and its functions, you must be wondering, “What type of information is indexed”? Well, by default, all the properties of your files, including full file paths and names, are indexed to enable Windows Search to find results faster. Files with text are also indexed to allow you to search for specific words in your files.

Windows Search uses protocol handlers, filter handlers, and property handlers to index a wide variety of file formats, including the following:

  • Office – .doc, .xls, .xlc, .pps, .ppt, .dot
  • XML – .xls, . xml
  • HTML – .asp, .aspx, .htm, .html, .ascx
  • Text – .cmd, .bat, .log, .url, .rtf, .ini, .asm, .asx, .txt
  • OneNote – .one

To view the full list of file types that can be indexed, follow the steps below:

  1. Press the Windows logo key on your keyboard and look for “Control Panel”.
  2. Choose “Large icons” under the “View by:” drop-down menu and click on “Indexing Options”.
  3. Click the “Advanced” button and switch to the “File Types” tab.

If you wish to change how much of a file’s information is indexed, here’s the simple guide:

  1. Go to Control Panel > Indexing Options and then click on the “Advanced” tab.
  2. Open “File Types”, and you’ll see two options: “Index Properties Only” and “Index Properties and File Contents”.

If you select the first option, the contents will not be searchable but you’ll still be able to search for your files by file name. While choosing to ‘index properties only’ may reduce the size of the index, some searches may take longer to complete.

File and Folder Exclusions

As for file types that don’t have an associated filter or extension, Windows indexes their system properties but not their contents. Likewise, Windows Search excludes files protected by digital rights management (DRM) or information rights management (IRM).

By default, some folders are also excluded from indexing. Here are a few examples:

  • %System%\Users\UserName\AppData\
  • %System%\ProgramData\
  • %System%\Windows\
  • %System%\$Recycle Bin\
  • %System%\Program Files (x86)\
  • %System%\Program Files\

Why Does Indexing Always Run on a PC?

Many changes occur to files on your PC every time you’re using it. Indexing keeps track of these changes and updates the index. To achieve this, the indexing feature opens recently modified files, inspects the changes, and indexes the latest information.

That’s why you may notice the SearchIndexer.exe process always running in Task Manager.

How Does Search Indexing Affect Searching on Windows 10?

Some people claim that search indexing hogs system resources on Windows 10 PCs and recommend disabling the service. However, this couldn’t be further from the truth. Indexing is designed to take place when the PC is idle. When the system is running, the process is paused.

However, sometimes the service may register high system usage in Task Manager, impacting your computer’s performance. When this happens, here are some troubleshooting steps you can try to fix the issue:

  • Restart the Windows Search service. Launch the “Services” window to be able to do so.
  • Run the “Search and Indexing” troubleshooter, which is accessible via the Control Panel.
  • Try rebuilding the index. Go to Control Panel > Indexing Options, and click on the “Advanced” tab. Go to the “File Types” tab, click on the “Index Properties and File Contents” radio button and click “OK”. Now, go back to the “Index Settings” tab and select “Rebuild”.

Where Is the Data Gathered From Indexing Stored?

All the index information is stored locally on your Windows computer in the C:\ProgramData\Microsoft\Search folder. The data is not sent to Microsoft servers or shared with any other computer, even on the same network. However, some of the apps that you install on your computer may be able to access the data. That’s why it’s important to install apps from trusted sources only.

Which Apps Use the Index?

The majority of apps on your PC depend on the index in some way. Take Cortana, for example. It requires the index to quickly search through the countless files on your PC and give you prompt results. Groove, File Explorer, and Photos all use the index to track and store changes made to your files to provide faster results the next time you look for a specific file. Outlook also uses the index to search through your emails and show you what you’re looking for.

In a nutshell, the index plays an extremely important role in enabling the apps on your PC to provide up-to-date search results for your files, folders, and other content. If you disable indexing, some apps that rely heavily on it may run slower or fail to function at all.

How Much Space Does the Index Occupy?

It depends on the size of the indexed files. Typically, the index should occupy less than 10 percent of the size of the indexed files. For instance, if you have 500 MB of text files, the index will use less than 50 MB.

Usually, the index size increases in proportion to the size of files on your PC. If you have countless small files that are less than 4 KB, they can end up occupying a huge percentage of your disk space.

Tweak Your Windows PC for Optimized Performance

When your PC starts to lag, it could be due to several factors, chief among them being PC junk and a corrupt Windows registry. Since you use your PC daily for work, gaming or streaming, you’ll find yourself installing and uninstalling apps, downloading files, and browsing, to name but a few.

As a result, your PC gathers all types of junk, such as browser cache, unused error logs, and Office cache. If these files are not removed, your PCs’ performance drops and apps start taking longer to load. Trying to manually clean your PC is not only cumbersome but also inefficient.

Luckily, there’s one tool that will help you fix everything with a click of a button.


Resolve PC Issues with Auslogics BoostSpeed

Besides cleaning and optimizing your PC, BoostSpeed protects privacy, diagnoses hardware issues, offers tips for boosting speed and provides 20+ tools to cover most PC maintenance and service needs.

Auslogics BoostSpeed is a product of Auslogics, certified Microsoft® Silver Application Developer

Auslogics BoostSpeed is an optimization program that comes equipped with all the essential tools needed to automatically fix speed-reducing issues, clean out PC junk and boost your PC’s speed. The program also allocates maximum resources to active applications and protects your privacy.

Auslogics BoostSpeed is a powerful yet lightweight tool that only uses a fraction of your system resources. The user-friendly interface allows you to access all the settings with ease. What’s more, you can automate system maintenance to allow the program to keep your PC running optimally at all times.

Do you have any questions about search indexing in Windows 10? Drop your comments below, and we’ll get back to you.