Sorry to post in a solved thread, but I have the same problem.
The difference is that I have an Acer Aspire 8930G. My GFx card went south for some reason almost 2 years ago. I just bought a new one, and installed it and upgraded my laptop from vista to Windows 7 ultimate x64.
But I'm stuck on standard VGA graphics card, and this is day 5 on trying to solve this.
Bpruhs wrote that it was solved by editing the .inf files in the Dell driver instead of the nvidia driver.
How? What did he/she do?