SL wont run, detects my FX5200 as GDI Generic?

Can anyone help me here, I have just installed SL and it wont even take me to the main screen with the buttons.
Nothing wrong with my card on the DirectX level, I have run DxDiag and I can run Unreal Tournament... what magic wand should I wave to see what's wrong with OpenGL?
What I've tried to do:
I am running the latest, WHQL-certified, official nVidia drivers. 66.93
I have tried removing my card from device manager and reinstalling my drivers using the nVidia-supplied EXE.
I have physically removed a PCI card I had put in yesterday in hopes of getting my PC to work with two monitors. (I could never get it to work anyway, there was some IRQ conflict or something)
I have installed my chipset drivers. It wont run with or without them.
I am running Windows XP SP2, fresh install from a few days ago... I have a firewall and antivirus too

Rt click on your windows desktop, select properties, select settings page, click on Advanced.

In the new properties window select the Troubleshoot page and make sure the Hardware Acceleration slider above NONE - pull it to the right over to FULL.

Thanks Uncle, it is on full. It defaults to full, and I've never changed it.
There is also a checkbox for "enable write combining".
It is checked. (No idea what it means.)
Setting it to "None", hitting apply then running SL results in the same message.
Setting it back to "Full", hitting apply, then running SL results in the message again.
Is there some log file I can send you or something?
Prior to reinstalling, I had Windows XP SP1 and SL worked great.
Are there any known problems regarding SP2? It seems to affect a lot of people in different ways, so, who knows.
I'll try running some other opengl-based game to see if it works.

Pontifex works but its really slow.
It reports my OpenGL vendor as Microsoft Corporation and my OpenGL card as GDI generic.
I assume this means its using some sort of MS software rendering device.
Very odd.

Eggy,
Before you installed the new nvidia drivers did you uninstall the previous ones from control panel/add/remove and then restart. Accept default and then install the new nvidia set. Just a swag.

There's also a chance that you have some remnant of something in the registry screwing your installation up. If you have a registry scanner/fix-it program like Norton WinDoctor (or any of a number of others) you might want to try running those.

had this happen with two monitors after i'd switch which minitor was primary and run WoW. Not sure if running WoW did it or the primary minitor switch but restarting fixed it. tried that yet ?

Lecktor wins! SL works now
I was removing the driver from device manager instead of the add/remove thing.

YaY !! Don't know why nVidia makes it so difficult but I discovered this way back with them and you absolutely have to do it that way. Glad that worked for ya Eggy.