You could go to HP and order a set of recovery disks if they are still available
http://h10025.www1.hp.com/ewfrf/wc/d...dlc=en&lang=en
If you read step 1, on some models you can create a set of disks but I don't think thats a option with your model.
If after following step 2 and the disks are no longer available from hp I am afraid you would have to purchase a windows retail disk and install the operating system. Then you would have to go to the hp website and download all the drivers.
hope this helps, its all I got