so my computer broke (aka Marks i need your help please)

[Plug Drugs]

TL;DR: so if you're wondering why i haven't been posting (not that any of you care about me) its because my computer broke and I don't know what's wrong with it. Right now I'm thinking its the processor, but my first guess was the motherboard.

So about a week ago I accidentally bumped the case with my knee, and hardware started making unidentifiable noises. I started getting blue-screens and random crashes, and sometimes BIOS wont even post and my monitor doesn't even light up. I usually get a crash/blue-screen after 10-15 minutes, and it takes me about 1-5 tries to get my computer to even log in.

Windows 7 repair (during start-up) didn't find any problems that it could fix, so I don't know what's up.

About 2 weeks ago my friend helped me clean off my processor and heat sink, and I'm thinking right now maybe he didn't apply the thermal paste right or something and my processor keeps overheating

I know it isn't anything in windows because sometimes BIOS wont even post.

The only other thing I think it could be is a heat-warped motherboard or something