...You may also want to check if your Model was shipped with a hidden Recovery partition...
It should, my Compaq does. It shows in Windows as the D-Drive and is labeled "Presario RP".
1. Power on the computer
2. Press F10 repeatedly when you see the HP or Compaq logo.
2. When the recovery screen appears, press Next and then Yes to perform a non-destructive recovery.
3. To perform a destructive recovery, click Advanced and then Yes.
4. After the recovery is finished, the computer will reboot.