I only have the Pro edition disc, and right now I can't get the 8.1 evaluation ISO because I'm about to burst my data cap. I'm gonna look for a Ubuntu disc in my drawers to back the files up. When I'm finished, I'll try to do an upgrade install of Windows 8. If it fails, I could try to factory reset to Windows 7.
The model of my PC is a Compaq Presario CQ1-2010AN, running Windows 8.1 Pro with Media Center.