Hi,
Sorry for the delay in responding to you. The forum spammers had killed my post notification messages.
Don't format the drive.
Use Recover My Files (
Data Recovery Software to Undelete Files; Disk recovery; Recover Deleted Files) to run a Complete Format Recover on the drive. Follow the instructions in the first sticky post of this forum (how to recover a formatted drive), searching only for the default file types and stopping the search when OS items gets high and stable.
If you do not find OS items it means that the old Master File Table has been destroyed, and you will only find files by their header & footer - which are the ones called "Recovered_Filetype_x"
Good luck.