My CPU & GPU gets overheated really easily [Computer freezing]

[Skyset]

Hello SF.

I tried getting an answer over at HF but I think I'll get a better one over here.

My GPU is always warm for some reason. It lies on steady 78-79 degrees Celsius. It still works fine, but my problem is my CPU. When I have Chrome, MSN and Steam running, this is how it looks like:



Then I start the League of Legends launcher, and BAM!:



What I have tried:
- Cleaned my computer from dust (vacuum cleaning).
- Checked the fans, they are all working, and one of them sounds like a jet plane nowadays for some reason.
- Reinstalled Windows, it's all clean but there's no difference.

When the temperature raises this much, my computer just freezes and I have to reset it on the power button. A friend of mine said it could be a memory (RAM) problem too, but I think it's connected to the high temperatures my CPU get since it always freezes when that raises.

Anyone know what I should do?

Thanks in advance.

- Skyset