ok, I've bough a laptop computer, it's a fujitsu siemens, with: ATi Xpress series video card, the cpu is a AMD Turion 2X with 1.60GHZ, and 2 GB RAM.

Now here is the deal, I don't know what it is, but something, is sometimes leeching some kind of performance, I've been using a virus program, one for spyware too, and adware, didn't find anything,

How does it drain performance?
well... I can clearly see the lack of performance when I'm playing games, and it is just on some games too, and sometimes, it's not there I got a feeling it has something to do with the cpu, the computer is a AMILO PA 1510 that can with Vista, I installed XP on it, and there is drivers for XP, so that should not be the problem I think.

It's lagging in games.

Yes it is, and as I said it's just sometimes, it's not always, and its not when the computer is warm/cold, because I've tried everything, though! its not normal lagging, it's in the same ryth or what should I say, the lagg does not stop, its only there when something is in 3d view, and it goes like: "-- . --. --. --. --. --." too long ones, and one short lagg, never changes, always same like that, it can't be that my computer is too bad, because, if I compare some games here:

Counter strike source: plays on high settings, and on high resolution, everything works VERY finy with no laggs and smooth!

Morrowind: laggy as hell, on all setttings

Serious sam 1: SOO laggy I can't play it, have tried all resolutions and so on.

Quake 3: also laggy, on all theese last three, it got the same lagg, in same rythm... I think this is really stupid.. why would morrowind lagg when counter strike source don't?

also, another game, Postal 2, had the same thing, but it jsutt randomly disappeared and I could play that game on high :S ... yes I got no idea whats going on,

PLEASE HELP ME!

things I think is can be

Direct X wrong?
maybe drivers... even though I've tried everything
settings?
I also read about something called cold and quite for my cpu, can this be the case? HELP! PLEASE!

I would say your CPU it is rather slow for games?Norton will use up ya speed to.