Windows search not finding files on one drive - Drive missing from indexer search roots

Question

_{Note: I have posted the same question a while ago on answers.microsoft.com, where I got no reply so far}

While trying to investigate issues with files not being found by the search indexer, I have noticed that there seems to be an issue with a drive missing from the search roots. Some details that might be important:

• The computer has three internal drives:

  • OS Drive C:, SSD, all the usual system partitions
  • Data drive E:, HDD, two partitions (the other one doesn't need to be indexed)
  • Data drive D:, Storage space, one partition

• In Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Search\CrawlScopeManager\Windows\SystemIndex\SearchRoots, the following entries are listed (note how the GUIDs seem to be the same for the D and E drives):

  defaultroot://{S-1-5-21-740414505-3273780380-2204535043-1001}/
  file:///C:\[d2ba34b2-ebef-456a-a0d6-8da93b88df93]\
  file:///D:\[3c8e34ff-7776-47f8-abaf-4334ed09d427]\
  file:///E:\[3c8e34ff-7776-47f8-abaf-4334ed09d427]\
  winrt://{S-1-5-21-740414505-3273780380-2204535043-1001}/
  

• The indexer diagnostics tool lists file:///C:\ and file:///E:\ under "Search roots", which contradicts the registry key

• Under "What is being indexed?", the tool lists only paths starting with C:\ and E:\, where the paths starting with E:\ are on D:\ in reality. The same list for excluded paths appears in the Settings app under "Searching Windows"

• The "Indexing options" dialog shows both folders on D:\ and E:\ as being indexed (when clicking on "Modify"). In the "Index these locations" view, no location from E:\ is actually listed

• The search mode is set to "Classic"

• I have tried to reset the search index several times already, both via "Rebuild index" and by setting HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Search\SetupCompletedSuccessfully to 0

What is going on here? Why is the Indexer diagnostics tool confusing D:\ and E:\? Why are locations from E:\ not appearing in the list of locations to index? Is there any way to add a drive to the search roots/let the indexer recreate them entirely?

Please let me know if any additional information is required

Answer 1

Finally found the solution to this problem: This solution is based on this answer, with some more details on how to actually fix the issue.

The cause

One of the drives was created as a clone from the other one at some point. This results in identical GUIDs for the two drives, at least as far as the indexer is concerned (these are not the standard partition GUIDs or similar). The GUID is stored in *:\System Volume Information\IndexerVolumeGuid, so it's quite straightforward to reset it apart from the permission issues.

The solution

This is what I did to solve the issue:

• Stop the Windows Search service, and set the start type to Disabled
• Open regedit.exe
  • Set the value SetupCompletedSuccessfully in HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Search\ to 0
  • Go to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Search\CrawlScopeManager\Windows\SystemIndex\SearchRoots, and delete all keys corresponding to the colliding drives
• Download psexec, and run the command psexec -sid cmd from a command line prompt with administrative privileges
  • The newly launched command line has system privileges, so be careful!
  • Navigate to the first colliding drive by typing D: (where D is the letter of the drive)
  • Go to the System Volume Information folder by typing cd "System Volume Information"
  • Delete the GUID file by typing del IndexerVolumeGuid
  • Repeat these steps for all colliding drives
• Set the start type of the Windows Search service back to Automatic and start the service again.
• The search index should now be rebuilding, this time without any issues. Note that all settings for included/excluded folders have been deleted, so you probably have to reselect them via the Indexing Options settings panel by pressing Modify