Like Larcher said, all hp's now ship with a recovery partition that you have to access from boot up by pressing F10. which will allow you to do a repair recovery, without losing data, or a full restore, which will wipe all data off and bring it back to factory default
If you want to format it and not have all the hp crap on it, if the unit came with a DVD or CD burner is go into the Start-Programs -> PC Recovery(think that is the folder) and create yourself a recovery media set. that way you can recover it back to the way hp shipped it if needed.