1) Click start
2) Click run
3) Click cmd
4) Type the disk letter you wish to run a scan on e.g. if its drive C, type cd c:\ or cd d:\ for drive D
5) If you wish to scan the system drive C, check disk will only continue after a reboot
6) Type chkdsk /r and press enter (if you are scanning the C drive you will be prompted with a message stating drive is locked, do you wish to run scan at next reboot, type the letter Y and press enter)
7) Restart your machine and allow your computer to be scanned (may take up to 40 minutes)