Fix Windows 8.1/10 Search Filter Host and Indexer High CPU Load Problem

This article will help you to fix a search indexing problems on Windows 10/8.1 that actually takes high CPU and Memory utilization by the Search Protocol Host and Search Filter Host processes. This is a problem that seems come in to Windows 8.1 and 10.

High CPU Usage of Search Filter Host and Indexer

At first, make sure you really have some problems with CPU load.

Go down to Taskbar, right click on it, run and look at your Task Manager (or just press Ctrl + Shift + Esc)..

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If your CPU load is high, check if the Windows 10 processes Microsoft Search Protocol Host (SearchProtocolHost.exe executable), Microsoft Search Filter Host (SearchFilterHost.exe) or Microsoft Windows Search Indexer (SearchIndexer.exe or SearchUI.exe) are highlighted with the high CPU load. As you can see, in my case the “Microsoft Windows Search Indexer” process uses more than 30% of the CPU and 3.2 GB of RAM (in normal mode, this process rarely uses more than 3% of the CPU and 100 MB of memory). If they are – you have this issues too.

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How to Fix Search Filter Host and Indexer High CPU Utilization on Windows 10?

The “Microsoft Windows Search Filter Host” and “Microsoft Windows Search Indexer” processes are designed to simplify the search for information on the local drives. These processes are a part of the “Windows Search” service and responsible for scanning the file system. All the information found is saved to the special database file (index DB). The following elements are indexed: the name and path of files, the time of creation, key phrases (if this document, text file or html-page), the document properties and other data. When you perform a search from the Start Menu, Taskbar or Cortana in Windows 10, the operating system doesn’t search the entire drive, but refers to a structured index database. Those, the search results are returned to the user much faster.

High CPU and memory usage by indexing processes indicates that at this moment the indexing service is working intensively on gathering information and rebuilding the search index.

Try to wait 20-30 minutes until the indexing process is completed.

If you want to quickly reduce the load of your computer, you can kill the searchindexer.exe process and stop the Windows Search service (it’s safe).

If you don’t use the search features in Windows 10, you can completely disable this service and prevent it from auto start. Open the Services management console (services.msc) and look for the ‘Windows Search’ service. Stop it and change the startup type to Disabled.

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Use the Indexing Troubleshooter

You can fix some problems with the Search service with the built-in tool the “Indexing Troubleshooter”. You can run it through: Win + X > Settings > Search > Seaching Windows > scroll to the down of the page and click “Run the indexer troubleshooter to resolve common searc issues”. Also, you can run the tool by using the command:

msdt.exe -ep WindowsHelp id SearchDiagnostic

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Click Next, select the option “Search or indexing is slowing down the computer”, click Next.

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Wait until the Troublesshoter find and fix the problems and reboot your computer. Check if this resolved your issues.

Rebuilding Search Index on Windows 10

If you often use the search features of Windows 10, you probably won’t want to completely disable the Windows Search service. You can change some of its settings instead.

Click the Start button => go into Control Panel. Make sure that you are in Icon view, not Category.

Go to Indexing options.

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The first thing you need to do is to modify what are the indexing will check at.

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Remove all the check marks except OS (C:) drive and click OK.

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Then go to Advanced indexing options and click Rebuild index button.

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Now you will see this message:
Rebuilding the index might take a long time to complete. Some view and search results might be incomplete until rebuilding is finished.

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Click OK.

What it does is at the top of the Indexing options window your indexing will go from whatever number it is to zero and it’s going to start building index again. Click Close.

Once you do that after a few seconds you need to look at your Task manager again and notice that the Search Protocol Host and Search Filter Host processes are taking much lower CPU load now.

You can temporarily stop the system indexing by suspending the Windows Search service for 15 minutes. Go to Control Panel > Indexing Options and press Pause button.

This can be done if the SearchFilterHost process prevents you from working, but you do not want to completely disable indexing services.

microsoft windows search protocol host high cpu

In some cases, it is more efficient not to rebuild the index, but to completely remove the index database file. To do this, run Command prompt with administrator permissions and run the following commands:

net stop WSearch

rd C:\ProgramData\Microsoft\Search /s /q

net start WSearch

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If these methods didn’t help you to fix the problem with the indexing service, start Windows 10 Troubleshooter from Control Panel > Troubleshooting > View all > Search and Indexing and just follow the wizard’s instructions.

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In some case users have reported that they can fix the search problem by disabling the Bing Search feature (can used by Windows 10 for local search processes). You can do this by changing the value of the registry parameter BingSearchEnabled from 0 to 1.

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You can apply such an action with the command:

reg.exe add HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Search /v BingSearchEnabled /t REG_DWORD /d 1 /f
I enjoy technology and developing websites. Since 2012 I'm running a few of my own websites, and share useful content on gadgets, PC administration and website promotion.
Cyril Kardashevsky


  1. The reasons to this issue are various, including bad drivers, many apps running in the background… The high CPU in my computer was caused by the drivers. After I used Driver Talent fix the driver, this performance improved.

    1. Very helpful. Thanks so much. Search indexer was taking up to 30% of my CPU causing noticeable slow downs in the programs, such as Excel, that I was running.

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