Recently I was gifted a Dell XPS 710 tower running WinXP SP3. It was running fine until today when I restarted and received a blue screen and the error "unmountable boot volume". In order to fix this issue I've attempted to boot from the Windows XP CD and run chkdsk. However when I attempt to boot from the CD drive I get a "Boot Device not Available" error. Next I made a bootable USB flash drive, but receive the same error as the CD drive. The BIOS recognizes the CD and flash drives, and they appear in the boot device list, but neither will boot. I've attempted to resolve this by re-arranging the boot order in the BIOS and switching IDE channels/setting jumpers on the drives themselves, to no effect. I cannot move the hard drive to another machine because the XPS is the only one that supports SATA drives.