Computer Lags, and glitches on a week old build. Help?

First off, here's my build that i got a bout a week back.

HAF X
i7 960
Rampage III Extreme
DDR3 OCZ 6gb (3x2) 2000mhz RAM
HD6970
OCZ Vertex2 160gb
1tb WD Caviar Black (sata3)
LG bluray burner
ASUS VE267Q
1tb external drive (WD
and im running Win7 pro at 64bit

some background:
i got all the parts from a shop, and they said theyd build it for me for free
so i let them
then when i brought my baby home, i turned it on, and it asked for a windows install disk because it couldnt find an OS on the system. after installation, i found out that there WAS actually it already installed but now its at windows.old
i was like meh
and installed all the drives for everything
but since then ive had over 7 crashes (that cant be good right?)
according to the .dmp logs, these are the things causing crashes

mv91xx.sys
ndis.sys
ntoskrnl.exe
atikmdag.sys

ive tried reinstalling drivers etc, but i still get crashes
and it lags (as in frame freezing in the middle of a Crysis game making you tear your hair of type of lag)
i mean a 6970 shouldnt lag on crysis =\

so ive come up with a brilliant idea
wipe the damn thing and restart
any ideas on how to do it? as i would like to ease EVERYTHING off my ssd, do i need to use like a linux boot disk or what?
can someone guide me through it?
any input welcome (unless its to bitch about my build. *** you, im happy with it)