Try downloading a copy of Windows and reinstall using the key on bottom of your laptop. You may have to search for an OEM version, not sure which your key is for. This will only reinstall windows though, you will have to hunt for drivers but you won't have all the extra bloatware they put on for you, the way a computer should be :) Torrents are your best friend in this situation. I'm about to try on a Toshiba Satellite A105, I'll let you know which version works.
