Eh, there's really no substitute for experience and knowledge, but look for an ISO image of Hiren's boot cd. This has all kinds of tools in it to test hardware with. As far as overheating goes, is anything too hot to touch? If so, you got heat problems.
But, Hiren's boot cd is awesome, and there are torrents for it all over. I think the current version right now is 7.9 Here's a link to what it contains. http://homepage.ntlworld.com/hiren.thanki/bootcd.html