Unexpected Floppy Seek

Hi guys, I have a Windows 2K Advanced server, which is doing absolutely nothing except functioning as a test DC in an AD network – no other role. Every 5 minutes or so, the floppy seeks for a few seconds -its just done it now and its driving me crazy!! Nothing interesting from system monitor – any ideas about what it might be, or where to start looking. Its sitting right in front of me and I’m starting to get obsessed, waiting for it!!
Thanks in advance,
Steve