All you need to do is boot off a workbench disk and run DiskSalv 2
DiskSalv2 might be a VERY BAD IDEA if using the NSD patched scsi.device from OS3.9!
DiskSalv2 doesn't handle partitions past the 4Gig barrier very well and can wipe out other partitions before the +4Gig barrier.
I'm not sure what the poweflyer uses to patch in, but I would suggest using
DiskMonTools on Aminet instead of DiskSalv2!
Whichever HD repair program you try, PLEASE FOR YOUR SANITY'S SAKE, BACKUP YOUR REMAINING PARTITIONS BEFORE PROCEEDING!!!
I can't stress that enough! I back up my harddrive partitions to CD-Rom every month or two, and there have been a few times I've been thankfull for doing so...and one time being that I once did attempt to use DisKSalv2 on a partition past the 4gig barrier, which in turn wiped my Work: partition (which was inside the barrier) accidentally. Had I not had a working backup, I would have lost MANY registered programs that I've spent good money on over the years.
Good luck, and PLEASE BACKUP THE DRIVE FIRST!!