In order to repair DISK0 Windows 7 it would have to have the EFI boot partition and the 100mb System Reserved partitions which somehow went away. Did you do anything to change them?
Just to double-check can you post up a screenshot of your maximized Disk Management map in the mini-XP by rightclicking Computer and choosing Manage?
You can rightclick on the DISK1 partition in both XP Disk Mgmt and Partition Wizard to Explore the disk to see if you see any files.
If so you can copy out to external your files: Copy & Paste - in Windows Recovery Console