Re: "without pre-installed software"
HP claims you can only do it once. Makes you wonder what happens if you end up burning a coaster. I guess you're out of luck. Seems very silly restriction.
I purchased my HP netbook from the now defunct Dick Smith Electronics. There was an application for backing up the install partition. I asked the salesman what happens if the backup didn't work. He said that DSE would reimage the hard disk; for free if the machine was still under warranty and a small fee if the warranty had expired. I'd assume other retailers of HP provide a similar service. The critical thing here is the Product Key and that was inside the battery compartment.
It was irrelevant to me in any event as I ran Ubuntu on the netbook until I sold it after reinstalling W7.