[Drivers] DX9.0L? Also problem with 8800GTS

Hi, basically I have two problems : one concerning Warhammer Online and Directx 9.0c and the other one concerning my 8800GTS and it's drivers.

First of all, I've tried to install Warhammer Online but it says that I need to download DX9. Is there a way to run it without installing DX9, what about DX9.0L?

Secondly, I've had a few problems with my 880GTS and the most recent drivers from nVidia. Now, I'm currently running Vista with the default drivers that came with SP1 (they are from 2007-09-12). If I try to install the latest driver from nVidia's website and then run World of Warcraft and alt-tab, I'll get a bluescreen or the following error : "Graphic drivers have stopped working and are now recovering".

Is there a way to fix that?

Thanks alot in advance!

You're saying that I should install DX9 on Vista?

I dont remember off hand if the 8800 is capeable of DX10
goto start|run and type dxdiag and see what version that you have and do the tests to see if you can run all of them.
then post back.
There was a time when changing nvidia drivers messed up direct x a little and the reinstall will fix it.
Strangely enough bad sound drivers can cause direct x to mess with video but i havent seen that much lately.