Got a used Aspire One for mom that came with Ubuntu OS installed. Windows keycode sticker says windows 7. I'm guessing someone replaced the windows 7 starter with the Ubuntu OS. Mom wants windowsinstalled. I have a licensed copy of windows home permium and an external cd drive I can use to install but, I need to know if it is compatable with the aspire and how to go about doing it since Ubuntu has partitioned the hard drive.