Computer overheats and/or freezes mostly when playing Maple Story

I have a desktop by the way.

@ Chuey: How exactly do I check the Disk Defragmenter data thing without deleting the files at first?

I'm sure these tech-savvies now more about what they're talking about. I've never had true issues like these. Their calls to aid you may be more useful.

As for Disk Defragmenter... just open the application and next to each drive is a percentage. Nothing needs to be done before or after. But I find doing a Disk Cleanup first more helpful.