is it on the same partition, hard drive? if yes, That could be a problem. You dont need drivers for installation of windows, what do you need it for?
vista on c drive and windows7 on d Used both and ok; then used only windows7 for 2 months. Booted into vista and told to reactivate. I made the phone call and recorded the activation numbers. Then did no longer boot into either. I used the repair in both and It never finished and reported couldnot repair. And i continuously get the error message : signed device drivers not found. They do not show up in my search of the hard drives or the install vista and windows7 disks.
since you reformatted, just reinstall. I dont know what the installer was complaining about.