
If you want to install Windows 7 on a brand new system with no previous version of Windows, save youself $80 or more and buy the upgrade version. You can install it and boot up, but you won’t be able to activate it.
Thanks to Paul Thurrott at the SuperSite for Windows, using this tip you can make it work and get it activated.
After performing the clean install, ensure that there are no Windows Updates pending that would require a system reboot. (You’ll see an orange shield icon next to Shutdown in the Start Menu if this is the case).
Then, open regedit.exe with Start Menu Search and navigate to:
HKLM/Software/Microsoft/Windows/CurrentVersion/Setup/OOBE/Change
MediaBootInstallfrom “1″ to “0″.Open the Start Menu again and type cmd to display a shortcut to the Command Line utility. Right-click this shortcut and choose “Run as administrator.” Handle the UAC prompt.
In the command line window, type:
slmgr /rearmThen tap ENTER, close the command line window and reboot. When Windows 7 reboots, run the Activate Windows utility, type in your product key and activate windows.
80 bucks in your pocket and a version of Windows 7 that you can activate. Thank you Microsoft.
[via Paul Thurrott - SuperSite for Windows]


That might activate it.. but wont it expire when the “rearm” times out..?
While the “rearm” command resets the activation clock, in this case I think its just only to trigger the activation to look at the OOBE registry change. I believe the MediaBootInstall registry change is what allows it to activate.
Once activated, no need to worry about timers, 30 day notices, etc. Activated is activated.
But I will find out, I just installed Win 7 on a machine and using this method was able to activate it. If it stops working later, I will certainly post an update.
thx… i will try it if this trick still working or nt
It should still work. I recently installed an upgrade version of Win 7 using this hack, with no problems.