Did you try this?
To use PC Restore:
Turn on the computer.
During the boot process, a blue bar with http://www.dell.com appears at the top of the screen.
Immediately upon seeing the blue bar, press .
If you do not press in time, let the computer finish booting (starting), and then restart the computer again.
NOTICE: If you do not want to proceed with PC Restore, click Reboot.
Click Restore and click Confirm.
The restore process takes approximately 6 to 10 minutes to complete.
To use PC Restore:
Turn on the computer.
During the boot process, a blue bar with http://www.dell.com appears at the top of the screen.
Immediately upon seeing the blue bar, press .
If you do not press in time, let the computer finish booting (starting), and then restart the computer again.
NOTICE: If you do not want to proceed with PC Restore, click Reboot.
Click Restore and click Confirm.
The restore process takes approximately 6 to 10 minutes to complete.