I had the exactly same problem, but figured out the solution by comparing the correctly-labeled and incorrectly-labeled drive permissions to each other. Incorrectly labeled drives were missing read access from the SYSTEM user.
So the fix was to..
1. Go to the "Security"-tab on the drive properties (right click drive -> "Properties")
2. Click "Edit..." -> "Add..." -> "Advanced..." -> "Find now"
4. Select "SYSTEM" from the search results
5. Click "OK" -> "OK"
6. Make sure the "Allow"-checkbox is checked at least for the "Read" permission of the newly added SYSTEM user
5. 2x "OK" again
7. Reboot
Hopefully this solves it for others as well. If the SYSTEM user is already listed on the drive's Security -tab, then obviously...