USB HD Failure, error- not readable or access

Hello,

OK... I've got a- CnM Lifestyle Mistral 400GB Portable Hard ( samsung on the inside, I think )that's recently become not accessible. It still gets picked up when plugged into a computer, its just not browsable and doesn't do the usual auto run.

I'd like to know if there are any apps out there that could help sort out the bad sectors ( am assuming that's what's up with it the master boot record messed up ). Some threw TestDisk at me but I wanna hear from the brethren of Kioskea.

All insights welcomed and appreciated