|It sounds like your hard drive might have died. Do you have Dell diagnostics that check it?|
If not, and you know the manufacturer of the drive, you can download a diagnostic from their website. You can find where to go using the web site below:
FWIW to XP users: When you click on the 'Command Prompt' you are just causing the 'Command prompt' to be displayed. This prompt gives you access to NTVDM.EXE, the 'NT Virtual DOS Manager'.