Problem while Defragmenting windows. Pls help.

The defragmentation keeps on restarting all the time with the message that the Drives Content changed and the defragment will restart.

I have even tried closing all the running application including norton antivirus etc so that it will not interfere with the defragment but stiill the same message appears. And the defragment never completes and it get restarted over and over again?

Please help me how to avoid this problem
Thank you