Verified answer

Turn off the computer.

Disconnect all connected devices and cables such as Personal Media Drives, USB drives, printers, and faxes. Remove media from internal drives, and remove any recently added internal hardware. Do not disconnect the monitor, keyboard, mouse, or power cord .

Turn on the computer and repeatedly press the F11 key, about once every second, until Recovery Manager

Under I need help immediately , click System Recovery .

When System Recovery prompts you to back up your files, select a backup option:

If you have already backed up personal files or you do not want to back up personal files, select Recover without backing up your files , and then click Next . Continue to the next step.

If you want to back up your personal files, follow these steps to create a backup.

Click OK in the warning that appears.

After the system recovery is complete, click Finish to restart the computer. Complete the setup screens and wait until the computer finishes the setup.

Once the setup is complete, turn off the computer, reconnect all devices and cables, and then turn on the computer.

Before using the computer, update and protect your computer. Reinstall any virus and security software that was installed before the system recovery.

Reinstall any software programs that were added after purchasing the computer, as well as any files that were backed up.

as PJ said try restoring it to factory settings , you can do this by pressing f11 repeatedly before the windows logo appears. this will bring up a menu that you can then choose system restore

here is the guide from hp's own site .

http://h10025.www1.hp.com/ewfrf/wc/document?cc=us&...

scroll down till you get to the section headed 'Recovery from the startup screen (during system boot)'

try restoring it back to factory settings