I am using Windows XP.
The LOCK CLI command seems to do the trick (I didn't even know it existed!).
I think the main problem is my lack of memory (128mb): Everest tells me "AGP aperature size is more than half of the system memory size. This may cause performance penalty". I highly recommend Everest to everyone, it tells you so much more about your hardware than windows does, it's free too.
I should order some memory, I feel sorry for my processor lol.
My graphics card is integrated and the driver hasn't been update since... 2004! I'll see if there is a newer one.