Dear help desk,
I have had several flash drives which have failed and I could not tell if is hardware related or soft ware.The flash drives have symptoms such as 'usb device not recognized,and they cannot be viewed and formatted in my computer or device management since they are not even visible.others,when you copy something,they display the folders as empty even though properties show that there is something.Iam using windows xp and have tried the attrib command to unhide hidden files but to no avail.I have also tried to check (show hidden files and folders)in the folder options but to no avail also.all the flash drives which cannot be detected power up.How can I know if a flash drive has a hardware/software related problem?can these problems be solved by any type of free software or is there any software that can solve most of these cases?please help.

Honestly considering how inexpensive these drives are now, simply physically destroy them and get some new ones.
They really aren't worth the hassles involved with trying to repair them..