This isn't so much a trouble shooting question as it is a general question about something I'm not sure about. Can I use a system repair disk made from a laptop to reformat a desktop PC? I know it's unlikely but I lost the one I made for my desktop and didn't feel like buying a new Windows disk.
I'm not sure, you can try it, but there's some things you need to be aware of if it does work. First of all, the desktop PC will have to have a larger sized hard drive (HDD) than the laptop. Second of all, if the desktop has a larger HDD, then you'll lose the difference in space. For example, if your HDD is 500 GB and your laptop 320, you'll lose 180 GB (the difference) unless you edit your partition. Third of all, many of your drivers will not work since they will be for the wrong machine, so you'll need to back up your current drivers first. I use Hiren's Boot CD and the programs on there to back up drivers.
If you're just wanting to reinstall Windows, see if your high school IT administrator has a Windows installation disc which is compatible with your machine's license. On the side of every machine, there should be a sticker with your Windows license. See if he has an installation disc, and you can re-install from the beginning, and use your own license. To the best of my knowledge, this is legal and you'll have most of the correct drivers.
Or you can be bold and try a Linux distribution. If you're just doing word processing and Internet surfing, it might be worth a shot.