Help - broken screen, wrong graphic drivers for external display

Hello,

Having broke my screen, I've transfered my hard drive to another similar laptop build, to have immidiate access to it.

It worked enough to view and access my data even though most of the drivers on the drive weren't corresponding to the machine's hardware.

Especially , the display resolution was wrong because the original machine had a basic GMA card/device and the replacement laptop had a dedicated one(ATI). Noticing that, windows vista offered to restart the computer to apply windows default drivers for the type of graphic card it had recognized. Of course it wasn't necessary at all, it was only for resolution comfort, I knew I'd make a fool the al machine and to use an external display via the vga port...

The problem is that as the graphic drivers have changed, the default graphic accelerator doesn't handle the external display...

I wish I could again accept vista's proposition to reboot and reinstall basic (default) drivers but I'm totally blind... The device I could have used to dispaly anything isn't suppported.

Is there any procedure that can help?

Thank you very much for any insights, I feel very stuck, in the dark...

Chaz