Why does Windows 7 repeatedly re-index my system?

Windows uses an index to perform fast searches through the Windows Explorer interface. On my Windows 7 system, I want to be able to search using the interface in the upper-right hand corner of the Explorer window. The index and search normally work fine.

This "system index" is what is affected by the Indexing Options in the Control Panel. I have it set to index all local drives. On my Windows 7 system index, I have about 800k files. Every few weeks, the index appears to be erased and all items are re-indexed, which takes a few days.

Why is this happening and how can I fix it?

Solution 1:

Like many other people, I have long ago given up on the Windows Indexing service, since it is not only too slow and slows down the computer, but has also become word-oriented so sometimes it misses finding documents that I know do exist, because I'm searching for a partial string.

Like in the answer by @K7AAY, I use the Everything search engine for file-names.

For searching the contents of files, I use Agent Ransack. Although it does not index the files, its search is rapid enough to go through thousands of files in a very reasonable time. It also searches raw text, so does not understand the inner structure of Office files, but nevertheless it finds the text with many options like regular expressions. It has a Preview panel that lets me view rapidly the context of the search-string in the found files for pinpointing the ones that are worth opening.

Agent Ransack also installs a shell-hook in Explorer, so I can right-click a folder and invoke it for that folder, thus limiting the search.

Solution 2:

Win7 indexes all files unless you disable that, as I did, by opening Windows Explorer, right-clicking on C:, selecting Properties and clicking on the circled tick box in the picture below.

When I need to search for a file by name, I do it with the Everything free app from http://www.voidtools.com/ which is much faster than Window's own search function.

Solution 3:

I don't have a 100% answer but some of the following may be contributing:

• Windows--at some point--needs to rescan files to make sure its indexes are correct. Generally this is done in the background. If your computer gets shuts off when not in use or has programs continually running keeping it awake, it could be disrupting the automatic indexing.

• If you have a slow storage device, it could be taking an excessive amount of time to scan that many files

  • You can configure what gets indexed under "Indexing Options"
  • You can still use Windows Search on items that haven't been indexed, but it will take longer to search these files

• Somehow the scheduled optimization tasks are messing up search

  • Windows has a couple Start Menu Optimization tasks in Task Scheduler
  • You can try disabling/running/checking the last run time on these to see if you notice anything

• You can open Event Viewer and search for entries related to Windows Search to see if it's encountering any errors or there's any related details in there

• Make sure the Windows Search service is set to Automatic or Automatic (Delayed Start). It's possible it's not always running and then has to catch up when it is opened again

• You can try rebuilding the search index in Indexing Options although it sounds like this is what Windows is sporadically doing anyway

As a side note, you may want to fix Windows Search rather than use 3rd party alternatives for the following reasons:

• Windows Search will search inside files including documents and PDFs (you may have to download an ifilter)

• Windows Search provides the results in the Start Menu so using the search functionality to launch programs doesn't work correctly if search isn't working correctly