The more radical (and effective) solution to any of the indexing problems is to reset the Indexing Options to defaults.
Since there is no official method to do this, one can use unofficial method, editing Windows Registry. The steps to perform are described here: https://superuser.com/a/963621/210811.
But hey, here is the copypaste:
- Stop Windows Search service:
Win + R, services.msc
, Enter
Find the Windows Search entry, click on it, and choose Stop from the left column.
Remove the following registry branch in its entirety:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Search\CrawlScopeManager\Windows\SystemIndex
You can use the free home edition of Registrar Registry Manager for this.
- Follow the step #1, but click Start instead of Stop this time.