so here was my drive before:
<Dell Recovery( R: )><Vista( C: )><XP( E: )><Ubuntu (ext2)>
here is my drive now, after repartitioning with Gparted from a Ubuntu LiveCD.
<Vista( R: )>unpartitioned<XP( C: )><Ubuntu>
After repairing the BCD, I was able to get into Vista. But when I got in, a bunch of core components failed to start. Then it loaded me into a temporary profile (i'm surprised it started at all). Well everyone knows you can't just change drive letters at whim, especially the system drive. So I went into the registry (to HKLM>System>Mounted Devices) and played around in there, and got my Vista back and operational. But I can't with XP, because i can't get into the registry. I tried restoring from a hive backup, but that didn't work. Safe mode and LKGC didn't work either. I can't repair the OS, because Setup doesn't even detect the fact that XP is already installed. Is there any way I can change the drive letters back for XP? How did these get changed in the first place??