Problem installing W7 Ultimate 64 bit

Hi everyone!

I wanted to install windows 7 ultimate on my pc. When I bought it 1 year ago, it ran windows vista home basic 64-bit, but my pc was very slow. The startup durated like 6-10 minutes and sometimes my pc freezes and I can't do anything anymore, even caps lock or num lock don't work anymore. So I bought windows 7 ultimate 64-bit and formatted all my hard drives. I started install it and when it's allmost finished, I get BSOD with message STOP IRQL_NOT_LESS_OR_EQUAL 0x000000A. I restarted my pc and ran it again, but same error. I looked on several forums and found that my rams could be the problem... So I get out 6GB so I have 2 left and do it again... Still the same error. So now I'm out of ideas and I ask your help.
Sorry for my (bad) english, I'm only 17 and from Belgium.

My pc specs:
Acer aspire predator G7700
Intel core 2 extreme (4 cores, 4 threads @ 3.00GHz)
8GB DDR3 RAM
2x Nvidia Gforce GTX260
2x Sata HDD 640GB
2x Sata HDD raptor 150GB
...
(ask if you need more information)

Greetings and I hope for a fast and positive answer...
(I need my pc for school )