What's causing the BSOD?

The most significant thing that I remember is downloading .Net Framework 4 manually along with XNA for 4.0 to play a game. After that, my computer (or laptop to be specific) seems to be running "busy". For example, I was just viewing a video on YouTube and suddenly the sounds doesn't work. This clue might be leaning to a driver problem, but right now, the audio is just working fine since then. Is the .Net Framework 4 the cause of the Blue Screen? Unfortunately, I didn't have any restore points during that time. Also, when I tried running Windows Update, which is relevant to .Net Framework, a lot of the updates fail (They fail to reconfigure during the restart). I tried re-installing .Net Framework 4, but I get an error now. All help would be appreciated.

Here's what I did: After all of this blue screen problems, I decided to return my laptop to factory form, which means I'm reformatting my laptop, so I don't have the .Net Framework 4 anymore, therefore I can't do the update reset you gave me. Unfortunately, the BSOD still shows up. I got 0x00000050 error yesterday. Right now, none so far, because I just turned my laptop on, but I'm pretty sure it will show up again, especially when I do something with my Windows Update. When I don't do anything with my Windows Update, it will just freeze. It has a buzzing sound when I'm listening/viewing something by the time it freezes. So I think the only option is the second one you gave me. I hope it works. TFYH!

Update: I'm downloading updates 1 by 1 and their succeeding.