Windows Search Not Working? Rebuild the Index
Windows search not working usually means the index went stale. What to check before you rebuild, what a rebuild does and doesn't fix, and how to search your own files without waiting for one.
A file you saved this morning has vanished from every search. It's still on disk; Windows has stopped admitting it exists. You type half its name into the Start menu and the results panel stays empty, or you open the folder in File Explorer, search inside it, and the results pane sits there blank while the file waits in the list in front of you.
Windows keeps an index behind those searches. When the index goes stale, every search leaning on it fails in the same minute, and none of them says why.
What the index actually is
The Windows Search service runs in the background and watches the folders it was told to watch. It reads the name, path, size, dates and, for most document types, the words inside each file, then writes all of it into a database called Windows.edb under C:\ProgramData\Microsoft\Search\Data\Applications\Windows.
That copy of the facts is why search feels instant. Explorer answers a question about a document without opening the document. Microsoft's own rule of thumb for the size is under 10 percent of the files being indexed, and the rule breaks in two places their page names: folders full of tiny files, and folders full of computer code. Both produce far more index than payload, because there is more to record about each item than there is item.
The records stay on your machine. Microsoft says so on its indexing page in plain words: the data is stored locally, isn't held by them, and isn't used to train anything.
Three things read the index, and only one of them looks like search. File Explorer uses it to find and track your files. The Start menu uses it for everything you type. Outlook indexes every email it syncs and leans on the index whenever it searches offline, while Edge uses it for history in the address bar. A stale index therefore turns up as Outlook losing mail and Edge forgetting your browsing, two complaints with no obvious link to a search box.
Three searches that fail differently
Telling them apart takes about a minute and saves you a rebuild.
Start menu search is the one that returns a blank panel, or no results for a program you installed yesterday. That points at the index, the SearchHost process, or the plumbing that merges web results into the list.
File Explorer search is scoped to whatever directory you're standing in. Inside an indexed one it uses the index and matches content as well as names. Inside an unindexed one it falls back to a slower walk of the filenames and quietly stops matching anything within the files. Names appear, phrases don't.
In-app search in Outlook, Edge history or Settings fails whenever the index is stale, even though the app window looks healthy.
The separating test is to search for a file you know sits in Documents. If that works and a directory on your second drive comes back empty, the index is running and simply never covered that drive. If no search anywhere returns anything, the service or the database is the problem, and the sections below apply in order.
Check before you rebuild
Open Settings, then Privacy and security, then Searching Windows. The status of the index is on that page, along with three controls worth reading before anything gets deleted.
The Find my files control offers Classic and Enhanced. Classic covers Documents, Pictures, Music and the desktop. Enhanced covers the whole PC, every user folder included. Most reports of search being broken come from a machine whose work lives on a D: drive or in a projects directory outside those four locations, where the index is running perfectly and was never pointed at the files. Switching to Enhanced fixes it and costs battery, which on a laptop is a real trade. The narrower fix is Classic plus Customize search locations, then Modify, then ticking the directories you actually use.
The excluded folders list sits on the same page. A directory parked in that list is the single most common reason a whole tree goes silent, and adding one by accident is easy when you meant to exclude a subfolder.
Indexing Options is reachable from the Customize search locations link, or by typing its name into Start. Its Advanced button opens a File Types tab where each extension is set to index properties only, or properties and content. A type set to properties only stays searchable by filename and invisible by content, which reads as broken search to anyone who knows the phrase is in there.
Task Manager adds one diagnostic. SearchIndexer.exe working hard during a rebuild is the job happening. The same process working hard every day on a machine nobody is filing anything into means something keeps invalidating the records, and a rebuild won't fix that.
Rebuild it properly
In Indexing Options, Advanced holds the Rebuild control. It deletes the database and builds a new one.
Microsoft puts the first index at up to a couple of hours. A rebuild over a few hundred thousand files runs longer, and the fan becomes audible while it does. Plug the laptop in first, since a machine that sleeps halfway through a scan resumes into a partial one.
Do it once. A second run restarts the clock from zero and doubles the wait.
Don't delete Windows.edb by hand. The rebuild in the dialog does the same work and leaves the service pointed at a database that exists. The manual route requires stopping the service first, and stopping it halfway is how a fixable index becomes a machine with no search at all.
Expect partial results while the new index fills. Searching during the rebuild returns what has been written so far, which is not an error and is not a reason to start over.
When the index isn't the problem
Four faults look like a dead index and none of them is one.
A search panel that never renders, or a Start menu that freezes the moment you type, is usually SearchHost.exe hung. Find it in Task Manager, end the task, and Windows restarts it on the next search.
Check the service directly. In PowerShell, Get-Service WSearch reports Running or Stopped, and Restart-Service WSearch in an administrator window restarts it. A service someone set to Manual during a cleanup pass leaves search degrading to a blank panel over the following weeks, with no error shown anywhere.
Corrupted system files break search in ways a rebuild can't reach. Run sfc /scannow, then DISM /Online /Cleanup-Image /RestoreHealth, then reboot and test again before rebuilding a second time.
The built-in troubleshooter covers the service, the index and directory permissions in one pass. In Settings, System, Troubleshoot, Other troubleshooters, it's listed as Search and Indexing, and on older Windows 11 builds that menu was called Additional troubleshooters.
One more thing that gets misdiagnosed. Windows 11 merges web results into the Start menu, and Settings, Privacy and security, Search permissions holds the toggles for cloud content search against a Microsoft account or a work account. Turning those off decides where a query travels and what appears above your own files. It has nothing to do with a file the index can't find.
The size problem underneath
Windows.edb grows, and that figure from earlier is a target rather than a ceiling. A directory of screenshots at 40 KB each, or a year of source code, pushes the database far past it.
Then the arithmetic turns circular. A drive with almost nothing free stalls the index, a stalled index looks like a broken one, and a rebuild needs room to write a second copy before it can drop the first. On a full disk the rebuild is the wrong first move, which is why the Windows disk-space guide belongs before this one.
DiskBrew draws the drive as rings you can drill into, so the directory eating 40 GB announces itself instead of hiding three levels down. DripCleaner clears caches and forgotten files and deletes only what you tick. Both install on Windows.
If searches corrupt themselves every few weeks rather than once, the index is a symptom. DiskSpeed measures sequential and random read performance against what the drive is rated for, and a solid state drive that has fallen well below its own numbers is a drive to replace rather than a database to repair.
Where the index stops
Four jobs the index will never do, no matter how many times you rebuild it.
Network shares and mapped drives are never indexed. A NAS holding years of project files stays invisible to Start menu search permanently, and no setting changes that.
Nothing inside an archive is indexed. A .zip is one file with one name as far as search is concerned, and its contents are a separate world.
Content matching depends on a filter for the file type. Where none is installed, Windows records the name and stops there, so the file is findable and its contents are not.
Encrypted volumes, and directories you excluded, are excluded by design. An index can only report on what it was invited to read.
A search that doesn't wait for one
FileSteep shipped its Windows build this week, for x64 and ARM64, and it takes a different route to the same answer. Point it at a directory and it reads what's there: full phrases inside documents, previews for most formats, a comparison of two trees, duplicate detection, batch renaming, and a terminal docked at the bottom of the window.
Because it reads the files rather than a database about them, it works on network shares, on excluded paths and on the drive Windows never indexed. Version 1.7.1, included with a membership, on the Frappe shelf beside the rest of the local tools.
The honest limit is speed. An index that's already built answers a whole-drive query in a fraction of a second; reading files directly takes as long as reading files takes. Use the index for the daily question and the app for the one that matters.
FileSearch does the name-and-metadata version of this on macOS today and hasn't been ported, so Windows users should skip that page for now. Both apps live on the Frappe shelf.
A routine that keeps search working
Find out which of the three searches failed before touching a setting. Check the excluded list and the Classic-or-Enhanced choice before rebuilding anything, since both are reversible in seconds and a rebuild is not.
After that, the discipline is mostly about space and scepticism. Keep a tenth of the drive free so a future rebuild has somewhere to write. If search breaks on a schedule, test the hardware instead of running a third one.
The last item is the one that outlives the others. An index is a convenience that can be rebuilt from the files in an afternoon. The files are the thing, which is why keeping the important work in ordinary formats in ordinary directories matters more than any of the settings above.
If you're also working on a Mac, the Spotlight version of this guide covers the same failure through mdutil and the Privacy list, and the slow-Windows guide covers the case where the machine is busy rather than confused.
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