login and immediate logout

So i'm here with my friend and he bought his brother's dell dimension 3000 since he had the same one...

we decided to put in his bro's graphics card (nvidia geforce 5500 fx 256mb) since it had 128 mbs more ram on it... same model just more ram

long story short, since the moment we put in the alternate graphics card every time we get to the login screen and login we get a flash of his desktop and immediately logged out... to no avail even in safe mode.

I've tried swapping graphics cards, trying to use on-board graphics and a bunch of other stuff.. basically any variable that might have had an effect.

So my question is, how do I fix this problem and be able to log in to the computer without being immediately logged out.

I've googled it and none of the problems that come up match out situation and the solutions that i've found require being logged in and able to access the control panel or something.

help?

Sounds like Windows' piracy protection ``feature'' shat itself somehow.

Time for hours of research, registry tweaks and dirty hacks or a reinstall.

help?
No thanks, I'm fine

You must have made your three hardware changes so now windows validation detects it as a new system

If you're not going to install Linux because of this, reinstall Windows.

Install Opera because it never crashes like this and uses way less RAM than windows

>>5
This.
And if you want to keep using your Windows key, you'll have to actually call Microsoft to be able to.

Unless you want to be a skiddie about it, of course.