Back to factory settings requires the Restoration Disk. (CD disk)
Turn the computer on, install the Restoration Disk in your optical drive, (Either one), and wait for the disk to boot up.
Once you come to the question of, "What do you wish to do; Non-Destructive Restoration, or Destructive Restoration, choose Destructive Restoration.
(Non-Destructive Restoration is Repair.
Destructive Restoration is a Full Installation )
After you click on your choice follow the instructions.
Takes an average of 35 to 45 minutes.
Don't have the Restoration Disk?
You can obtain it from HP Support. (HP bought out Compaq)
The disk/s are free. The shipping and handling is not.
$17 for a 5 to 7 day ship, $24 for a 2 to 3 day ship.
In the USA the phone number to call them is toll free.
(Big deal if you have unlimited service, or a cell phone, huh?
I just included this info anyway)
24 hours a day, 7 days a week.
(I called this number to verify it's a working number, and the procedure is still the same, about 2 months ago. It's a working number. No charges are involved)http://welcome.hp.com/country/us/en/contact/phone_assist.html
For HP Support phone numbers not in the USA,http://welcome.hp.com/country/us/en/wwcontact_us.html
You will need your Serial Number, (S/N), to give to the nice representative on the phone.
This is either on the back of your computer tower, or up on the side of the tower.
It's in the white Service Tag.
If you have questions please post in a Comment.
Would appreciate hearing how this came out.