Upgrade disc are generally meant for those who are upgrading from a previous operating system. If you perform a clean install using the upgrade media and try activating Windows, it wonâ€™t work. But Paul Thurott from WinSuperSite Blog has figured a work-around to use Windows 7 upgrade media to perform fresh full install of Windows 7. This means, instead of purchasing the regular copy of Windows 7, you can go for Upgrade disc and save $80 immediately! Unlike Vista, where you had to install the OS twice to be able to use the upgrade media to perform clean install, there is a much simpler alternative for Windows 7. This is how you do it:
1. Perform a clean install of Windows 7 and make sure there are no pending updates in Windows Update. Now go to Start Menu and type â€œregeditâ€ and press the enter key. (UAC will show up, if enabled).
2. Navigate to HK_L_M\SOFTWARE\Microsoft\Windows\ CurrentVersion\Setup\OOBE
3. Change the value of MediaBootInstall from â€œ1â€ to â€œ0â€
5. In the command prompt, type: slmgr /rearm and press enter. Thatâ€™s all. Now try activating Windows 7 using your product key, it should work.