I happen to be on HardDrive #7 and #8 due to a bad power supply.
However, due to the ability to read FAT32 partitions in floppy-booting DOS, I have not lost much. It may have taken a couple hours of power cycling, and copying like mad for 60 seconds before the disk destabilized and went whirr-scrape-clunk, but it was done
Backups are very important and will save you a ton of hassle when murphy inevitably comes to visit.