I'm troubleshooting a laptop for a friend, and her computer will not boot into Windows 7 at all, no matter what I do. I've tried normal startup (logo loads but doesn't go any further), repairing using the recovery partition (same thing), using a repair disk (same thing), an install disk (loads through "Windows is loading files..." but then sits at a black screen), and safe mode (stops loading after avgidsha.sys). UBCD won't load (BSoD stating that acpi.sys is the problem), nor will Hiren's Boot CD (same problem as UBCD). Linux distros load fine, but that's it.
I did run a BootDefender boot disc virus scan and it found several viruses, but they've been removed and all of the same problems persist. I'm at my wits' end and have no idea what to do because I can't access anything in Windows, not System Restore or anything.