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Windows Search indexer using high CPU or disk

Windows is building its search index. It's busy after big file changes and settles down by itself, but you can make it do less.

Published October 13, 2026. Steps are for Windows 11 and 10.

What it is

SearchIndexer.exe (Microsoft Windows Search Indexer) keeps a list of your files and their contents so Start, File Explorer and Outlook can search quickly. SearchProtocolHost.exe and SearchFilterHost.exe are its helpers that read inside files.

It's busy after you copy lots of files, add a drive, sync a big mailbox, or after a Windows update. With Enhanced search on, it indexes your whole PC instead of just your user folders.

Is it safe to end?

Ending it does no harm, but Windows starts it again. Usually it settles within an hour. If it's busy every day, give it less to index.

Index fewer folders

  1. Windows 11: open Settings → Privacy & security → Searching Windows. Windows 10: Settings → Search → Searching Windows.
  2. Choose Classic instead of Enhanced. Classic indexes only your libraries and desktop.
  3. Under Exclude folders from enhanced search, add folders full of files you never search: code projects, game libraries, virtual machine disks, backups.

If it never finishes

A damaged index can make it work forever. Search Start for Indexing Options, click Advanced, then Rebuild. Search results are incomplete until the rebuild finishes.

If you never use Windows search, you can turn indexing off: open Services, double-click Windows Search, set Startup type to Disabled and click Stop. Searching in Start, File Explorer and Outlook becomes much slower.

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