Computer Randomly crashes after cleaning

[First Time Randy]

So, about a week ago, i felt my computer was running slow. So I decided to completely wipe my drives and re install windows. And it was working completely fine. Then, I decided to put in a new hard drive, but I wanted to clean in out first. I cleaned it out, and then it stopped working. The computer would turn on, but the screens would be completely black. My cousins fixed it by taking out the graphics card, and ram and putting them back in. It worked fine for a couple hours then it turned off. Now, randomly it will shut off. Any help please?

 

[jinksy]

did you knock the heatsink?

 

[First Time Randy]

did you knock the heatsink?

I avoided that area completely, so I don't think so.

 

[jinksy]

can you login to Windows and check the error logs, see what caused it

 

[First Time Randy]

How exactly do I do that?