You might try the free download "diskeeper lite" from

www.snapfiles.com

It will run long the first time. It is meant to be run often. Every two or three days would be good. It will run quickly after the first time. I run a diskcleaner to remove temp files and clean out the recycle bin and finally diskeeper lite to defrag the drive.

Screen saver interferes the disk defrag. As a result the process has to restart and the disk defrag progress drops to 0%. The Drive's contents changed: restarting ... message displayed during a disk defrag, refers to this problem.

Running applications like your installed programs (firewall, anti-virus, ... software) or Windows service programs (Print Spooler, Windows Audio, ...) interfere the disk defrag. As a result the process has to restart and the disk defrag progress drops to 0%. The Drive's contents changed: restarting ... message displayed during a disk defrag, refers to this problem.
These programs run in the background and you may not have shut them down prior to trying to scan disk and defrag.

was able to defrag by ctl-alt del and ending the tasks running in the background. all but explorer and systray.

thanks to many other's on this site.

Two options: During a boot, tap the F8 key or go to Start/Run/Msconfig/Boot.ini and check off /SafeBoot/Apply, reboot.