In Windows, running a disk check can clear up many problems. Many small glitches can be cleared up with the chkdsk command.
Setting it up in the command prompt is easy, but counter intuitive. Open the Command Prompt by clicking the windows Icon and typing cmd and enter in the box.
Now type chkdsk /f C:
Windows does the usual thing and tells you can't do that here.
Type in y for yes and then exit the Command Prompt.
Now, reboot the machine and wait for all the checks to run. The normal "chkdsk C:" merely scans a disk, "chkdsk /f C:" scans and fixes problems, so you may be waiting awhile. Hopefully, it is worth it.