I ran into this problem on a Dell XPS 400 with SATA RAID 1 (Intel Matrix Controller) running XP Media Center Edition, and here is how I was able to recover. 1. Removed both drives. 2. Mounted drive 0 in an external USB enclosure and booted into GPartEd (available on Ultimate Boot CD and elsewhere). 3. Tried to view disk contents to no avail. 4. Mounted drive 2 in an external USB enclosure and booted into GPartEd. 5. Viewed disk and verified contents were visible. 6. Used Partition Image tool to back up partitions (optional step). 7. Connected drive 2 back to SATA connector (port 0 this time) and verified I could boot to Windows. 8. Mounted drive 0 in an external USB enclosure and used one of the GPartEd tools to erase MBR and related data (without doing this the array controller insisted on trying to boot from this, the corrupt drive when both drives were attached). 9. Connected drive 0 back to SATA port 2. 10. Booted to Windows and used Intel Array Console to rebuild array.