I get an error message that "The disk is in use or locked" when I try to WIPE a volume with KillDisk.

If this error occurs, you should boot from the bootable media utility and try again.

If the error still occurs, there may be a problem with the integrity of the file system. You should run a Check Disk first to correct any errors. Run "CHKDSK /F". Check Disk can be run from within the Utilities group in the Windows boot environment.