From: Robert
I don't have the installation disk, I have one for vista but I don't want to install Vista on a laptop designed for windows XP and only 2 GB of RAM
Vista was a terrible release. I wouldn't recommend it for anything.
I've refreshed a bunch of old 2GB XP laptops with windows 7 and they work fine (for basic web surfing type tasks).
Your laptop may have come with a restore partition on the hard disk. Lots of machines have it. You need to press a certain key at boot time and get into the restore process. That brings it back to factory condition. Make/model?
As mentioned, the program you referenced is just for wiping the drive out and making it unreadable. You still need to install an operating system afterwards. There's no need to do the wipe unless you're feeling overly paranoid about something currently on the disk. It's not unusual for companies to demand a wipe program before getting rid of equipment. My company demands full destruction of all drives.