From the information you provided, it is hard to determine where the error may be. Diskeeper will not defragment a drive if it is in a "dirty" condition and will give you an error if the drive is in this condition. (Since data integrity is a primary concern, Diskeeper will not perform a defragmentation on a "dirty" drive.)
It appears that you may have hard drive problems and I would suggest you run the following command assuming your hard drive is drive c:
chkdsk c: /f
This should fix and errors on your drive. If this doees not work and you can get run the operating system, you can shut down the Diskeeper service by going to Control Panel-Administrative Tools-Services and stopping the Diskeeper service and setting the start mode to manual. This will shut down Diskeeper and allow you to fix the problems with your computer.