I was finally able to turn 3D on in Vista 32 bit on my laptop. I hope this can help some others who have been having trouble. I have a Dell laptop with an nvidia 8600m GS vid card.
I just removed my current nvidia drivers and downloaded older ones (version 168.12) from www.laptopvideo2go.com
. Dell doesn't normally support generic nvidia drivers, but this site gets around that.
You can also go to guru3d.com to get older drivers as well for most desktop cards. I'd stick with versions around 168.xx if possible.
You may want to run drivercleaner as well to make sure you don't have any pieces of old drivers around. I'm sure some of this has been posted before, but I've been searching this forum for a solution to my problem and didn't find much except a few suggestions to try different drivers. I thought I'd be more specific. Hope this helps!