Well, I reformatted and it was working fine. Then I installed SP2 and bam, half of my programs stopped working, I started getting huge memory lags, explorer started failing on me every other time a opened a folder, and of course the network stopped working again.
I decided to screw it and reformat again without SP2... voila, everything works as nice as possible with a windows machine. Kind of gets you thinking, doesn't it?
Thanks for the attempts at helping me.