Windows 7: Win 7 keeps freezing and restarting itself randomly, please help!

Hi ya there ppl, been having some problems with comp lately and it asked me to run a WMD scan which I did, it ofcourse got stuck in a loop not finding any problems so I used the command to remove it. Logged back into Windows and now it just keeps freezing, crashing, restarting and even a random BSOD or two. Now i'm no IT wizz but it obviously is having some probs with the CPU, MB as I have noticed the CPU been getting rather hot. Cant do much with it as it wont stay on for longer than 10 min or so before either of these incidents happen, any advice on what to do to help solve or figure out what part of my comp is broken is greatly appreciated!