I just picked up a dc5800 with a bad HD, it did come with some OS software. It has 2 Vista disks, an XP disk(?), hp diagnostic disk, and a recovery disk. The case says its running Vista business downgrade to xp(dont know what that means). I replaced the HD and have had no luck installing the OS or even formatting the HD. When i put the Vista disk in it tells me to put the recovery disk in. When i put the recovery disk in, it says its the wrong disk. The hp diagnostic disk runs and detects all the hardware with no errors. Is there anyway to access the actual boot menu so i can format the drive, the intel bios doesn't have that option. I would suspect the b.s. hp software is the culprit. Any ideas?