Win7 Upgrade Activation after Clean Install Registry hack (Method 2) Extracted from: <http://www.winsupersite.com/win7/clean_install_upgrade_media.asp> Note: This workaround is not supported by Microsoft but my understanding is that it has a 100 percent success rate. If you are nervous that performing this workaround will lead to later complications --- unlikely, but not impossible --- please use Method #3 contained in the link shown above. Method #3 is supported by Microsoft, but it's a lot more work. 1. Ensure there are no pending Windows Updates to install. (Some of these can cause this method to fail. If so, install the updates and reboot PC. Re-run following steps.) 2. Open regedit.exe and navigate to: HKEY_LOCAL_MACHINE/Software/Microsoft/Windows/CurrentVersion/Setup/OOBE/ 3. Change MediaBootInstall from "1" to "0". (Double-click it and then enter 0 in the dialog that appears.) 4. Close RegEdit. 5. With Admin privileges, open Command Prompt. 6. In the command line window, enter: slmgr /rearm 7. Wait for the "Command completed successfully" dialog box. 8. Enter Exit to close the command line window, and reboot. 9. When Windows 7 reboots, run the Activate Windows utility (Win+Break, scroll to bottom and click on 'Enter Product Key'), type in your product key and activate windows. If it works, you're all set. You're done. Congratulations. If this does not work, see comment in Step 1. If that doesn't work, you can try different methods found at: <http://www.winsupersite.com/win7/clean_install_upgrade_media.asp>. (Win7_ActUpgrd-CleanInstl.htm)