I get the message "FAT is corrupted. Please connect device to PC to........".

I connect my SanDisk Sansa Clip (4 gig) to the computer but the computer does not recognize my player sometimes or the computer displays that the disk needs to be formated. I went into Explore, but cannot find any evedence that it is connected. Does it need to be returned or is there a way to fix this?

Bonita, August 2012