How to Fix Search Indexer High CPU on Windows

What Causes This?

Search Indexer (SearchIndexer.exe) scans files, emails, and other content so Windows Search can return results quickly. CPU usage spikes when the index is rebuilding, when too many folders are included, or when the index database becomes corrupted. It can also happen if background clutter, disk errors, or heavy startup activity keeps the service busy longer than normal.

Common Symptoms

• SearchIndexer.exe shows high CPU usage in Task Manager
• The PC feels slow when typing in Start or File Explorer search
• Fan noise increases or the laptop gets unusually warm
• Search results are incomplete, delayed, or keep changing
• CPU usage drops only after long idle periods

How to Fix It Manually

1. Confirm Search Indexer is the problem

   • Press Ctrl + Shift + Esc to open Task Manager.
   • Click More details if needed.
   • On the Processes or Details tab, look for Microsoft Windows Search Indexer or SearchIndexer.exe.
   • Check whether it is consistently using a high amount of CPU.

2. Pause heavy indexing by reducing indexed locations

   • Press Windows + S, type Indexing Options, and open it.
   • Click Modify.
   • Uncheck folders you do not need in Windows Search, especially:
     • Large download folders
     • Developer folders
     • Backup folders
     • External drives
   • Click OK, then Close.
   • Fewer indexed locations means less scanning and lower CPU usage.

3. Restart the Windows Search service

   • Press Windows + R, type services.msc, then press Enter.
   • Find Windows Search in the list.
   • Right-click it and select Restart.
   • If Restart is not available, click Stop, wait a few seconds, then click Start.
   • This can clear a stuck indexing process.

4. Run the Search and Indexing troubleshooter

   • Press Windows + I to open Settings.
   • Go to System > Troubleshoot > Other troubleshooters.
   • Find Search and Indexing and click Run.
   • Select the symptoms that match your issue, then apply any recommended fixes.
   • On older Windows 10 builds, go to Settings > Update & Security > Troubleshoot.

5. Rebuild the search index

   • Open Indexing Options again from the Start menu.
   • Click Advanced.
   • Under Troubleshooting, click Rebuild.
   • Confirm the prompt.
   • Rebuilding can temporarily use CPU, but it often fixes a corrupted index that causes constant high usage. Leave the PC on and idle until indexing finishes.

6. Check for disk and system file problems

   • Right-click Start and choose Terminal (Admin) or Windows PowerShell (Admin).
   • Run this command:
     • sfc /scannow
   • After that finishes, run:
     • DISM /Online /Cleanup-Image /RestoreHealth
   • Restart your PC when both scans complete.
   • Corrupted system files can keep Windows Search from working normally.

7. Reduce background load at startup

   • Open Task Manager with Ctrl + Shift + Esc.
   • Go to the Startup apps tab.
   • Disable non-essential apps with high impact.
   • Reboot the PC and check CPU usage again.
   • If the system is overloaded at startup, Search Indexer may compete for resources and stay active longer.

Fix It Automatically with Kudu

Kudu can help lower Search Indexer CPU usage by cleaning system clutter, reducing unnecessary background load, and improving overall Windows responsiveness. Instead of hunting through startup apps and cleanup tasks manually, Kudu handles the common performance issues that keep indexing busy longer than it should.

Download Kudu Free →