Computer is acting strangely, random lockups

I really don't know how to explain it other than my system is locking up totaly for a few seconds at a time.. it first started playing Halo, i thought it was just the game but when i got onto the desktop it still did it. What happens is the mouse, keyboard, anything moving or making noise(noise skips just like a CD) just locks and a few seconds afterwards it goes back to normal and everything running resumes.. I have never had anything like this happen so im clueless on what it is.. I don't know if it would be hardware or software anyone have any ideas or some things to check?

I have ran Disk cleanup, disk error-Checking(system error+bad sector), disk defrag, SpySweeper, Ad-Aware6, AVG6.0, McAfee, and Spybot Search and destroy

System in Sig

I think it might be one of my raptors, one of them is making a clicking noise... backing up files as i type this

Well lol, this is funny i got both of my raptors sitting outside my case right now upside down, seem to be working just fine.. this is funny but at the same time really sucks, guess im gonna have to leave my hard drives upside down and save some money for some 76gig raptors

You might want to try running the diagnostic software for the drives. Might alert you to a pending disk failure.