Try this
To use PC Restore:
1 Turn on the computer.
During the boot process, a blue bar with
Learn about Dell's laptops, desktops, monitors, printers plus computer electronics & accessories. appears at the top of the screen.
2 Immediately upon seeing the blue bar, press <Ctrl><F11>.
If you do not press <Ctrl><F11> in time, let the computer finish starting, and then restart the
computer again.
NOTICE: If you do not want to proceed with PC Restore, click Reboot in the following step.
3 On the next screen that appears, click Restore.
4 On the next screen, click Confirm.
The restore process takes approximately 6–10 minutes to complete.