1T My Book files are missing how can I retrieve?

Hi All

I have a 1T My Book that I use to store my live concert music files. It had 600 Gig’s on it this weekend. When I went on it yesterday all that shows up is about 30 gig’s worth. The  properties still shows that 600 gig’s has been used.

How do I find those now invisible files ?

Thanks

Kevin

PS My computer uses  windows XP

Either the drive is corrupted or virus infected

use a software to recover the corrupted files