Long story short, Windows 7 won't boot, and the "startup repair" routine just hangs. Not sure what is corrupted, if it's the MBR or what. Anyway, I was able to boot the live Ubuntu USB and move most of my personal data off the C: drive onto an external drive. If necessary I can reinstall Windows, but I'd rather try to repair it first if possible. Is there any way to diagnose/repair Windows boot problems through Ubuntu?
Using a Windows 7 install/repair DVD/USB you can fix your Windows 7 installation.