I updated through Windows Update, which I think included some component drivers, and reinstalled iTunes which then caused Windows (7) to download new iPhone drivers automatically. Now the computer reboots over and over after the black 'Starting Windows' screen, and the startup repair utility fails to find a solution and returns this error in the 'more info' thing:

ProblemEventName: StartupRepairOffline
... then some other things that didnt seem too important, then..
Problem Signature 07: BadDriver

From Googling around the solution is to start up in safe mode and disable most drivers but I can't get into safe mode at all, it just keeps rebooting. I'm posting this from a separate Windows 7 partition on the same hard drive - anything I can do from here? Or is my only option to wipe Windows and start again.

If you can get to Safe Mode with command prompt via F8 at boot up. (it may work fingers crossed).

You could try a System Restore to hopefully resolved the problems.

At the command prompt, type rstrui.exe, and then press ENTER. If you are prompted for an administrator password or confirmation, type the password or provide confirmation.

Sam, any resolution to your problem?