if you have a windows disc, pop that in, boot from it and then when the first menu comes up, hit “R” for repair.
Once that finishes, it will ask you to pick your windows install (it will say C:\WINDOWS) pick that one (1 or 2, whichever it is)
Once that comes up, types chkdsk c: /r /f
It will run a chkdsk and fix any errors in your windows install. That should fix your problem.
If you dont have a windows disc, just load windows like normal, start up cmd, type chkdsk c: /r /f
It will say:
The type of the file system is NTFS.
Cannot lock current drive.
Chkdsk cannot run because the volume is in use by another
process. Would you like to schedule this volume to be
checked the next time the system restarts? (Y/N)
type “Y” and then restart, before windows loads, it will run a chkdsk