I have 2 80 Gig HD's with a RAID setup to mirror each other. My PC has worked well for over a year now like this. Just this week, I got a warning at start up "Imcomplete Raid Configuration" - "Press F4 to configure" I pressed F4, and got a different screen showing 2 Physical drives, and options to create, detele, and other things. I was not quite sure what I was looking at, so I cancelled. If I cancel, it still boots up, but I don't want to damage my PC any further.