Funky N screen of death after reloading VGA driver

I've just been rebuilding my old Athlon XP/MSI motherboard system with a Gigabyte GA-MA785GM-US2H motherboard and Phantom II X3 BE CPU, running XP SP2, with 4 G of RAM and a 200GB IDE drive.

I'm on my 4th try here, having repeatedly run into the 'funky N' screen of 'nothing gonna happen' and increasingly wiping the drive each time. First time it wouldn't run, I tried to repair Windows. No go. So I tried to load a new windows and keep personal data. No go. So I went and backed up the personal data (I know, I should have done that first. Meh!) and installed new Windows. That went well up to a point. When I rebooted after the first software install, funky N. So I reformatted the booger on another system and started clean.

After that it was running fine and I was installing software (all of which ran fine on the system before), rebooting between each install, then noticed that the VGA driver hadn't loaded all the way. Reloaded it from the CD and crash, with the funky N on reboot.

What can I do to keep from having to reformat and reload (again)? Anything at all?

Thanks, I'll give that a go and report back...

put on all the service 3 first.. and all windows updates (after sp3)

might take 3 reboots to do all the updates...

then put on ati drivers