XP defrag HDD problem

im trying to defrag my HDD and when i run the disk defrag tool it freezes and freezes my computer then i have to restart my pc
its a hitachi HDS721616PLA380
it has 52% free space
also my CPU is using 100% almost all the time if not 100% its always greater than 90% but i think this could be to do with the defrag problem

 

Is the CPU over 90% all the time, even when not running defrag? If so, then this could very well be the cause of the defrag problem. Running defrags requires some free CPU resources so the files can be shuffled around and compressed as needed. Take a look at the Task Manager (ctrl + alt + del) and which apps are using up the CPU resources and either shut 'em down, uninstall 'em, or disable them. Norton and esp. McAfee are notorious for causing unneeded CPU drain. Lately, I've seen Spyware Doctor running away with CPU resources on several PCs. You may want to read this article about basic system maintenance, and maybe check for malware using the Major Geeks Guide to Malware Removal. You can also try using a 3rd party defrag program; I like Auslogics, but it will still require the CPU usage to be an acceptable level.
Good luck!
:-D

 

its runny over 90% all the time,
i have O&O defrag program so ill try with that and ill try the malware removal
thanks for the advice