Can't retrieve backup files on the removable HD

:sad:
Please help!

I've a 60 gig fujitsu 2.5" HD in a USB 2.0 case.

When I try to backup files to the removable HD, some files can be read normally afterward but some files can't be opened again and win xp pop out saying that chkdsk is necessary. When I run chkdsk on the drive, my backup files are all gone but it still take up space on the harddisk.

Do anyone know what's the problem and can my backup files be retrieved again?

Thanks in advance for your help!!

you can try and retrive your backup files by using a file recovery program, tuneup utilities has a function. I would personally, retrive my backup files and then format the hdd.