* Install Windows 7 on the computer
* Disconnect from the internet (RJ45 out, wifi off) and stop it from making any update through Windows Update.
* Open the Registry Editor Start -> regedit
* Go to key HKEY_LOCAL_MACHINE/Software/Microsoft/Windows/CurrentVersion/Setup/OOBE/
* Edit MediaBootInstall from 1 to 0
* Close regedit
* Start -> cmd to open MSDOS invite window, right click inside the window then "Execute as an administrator"
* Then type : « slmgr /rearm » and confirm with enter
* Reboot and when Windows 7 is loaded, start the activation program. Insert your key and activate Windows.