Defragment

Dell Dimension B110

 

       I can't defrag at all. I can't check disk either. Everytime I try to check disk it says it needs to beable to get to exclusive files, and would I like to schedule for the next time I turn on the computer.  The computer  automatically does check disk everytime I turn it on already. I haven't scheduled anything. And defrag won't do anything because check disk is somehow scheduled to run.

 How can I stop this so I can finally defrag my computer, it really needs to be defragmented. :smileysad:

I'll take any suggestions.