By default Windows 10 was offered as a free upgrade from Win 7 or 8.x. Those people who have upgraded to Win 10 may reinstall it freely on condition they have a product key of the previous version of Windows.Because Microsoft cancel free upgrade possibility the only way is clean installation (without previously installed Win 7 or 8.x).
If you want to make install Windows 10 directly and – on the same PC. You may follow the steps below:
- Download ISO image of Windows 10 from Microsoft website. Remember that you the version of the system depends on the version of your previous system. It means that you will be able to install Pro version only if you have Pro version of Win 7 or Win 8. Otherwise you must install Windows 10 Home version.
- In the ISO image find the program gatherosstate.exe, copy it to the Desktop and run as Administrator (right-click, choose Run as administrator). The program read your licence and hardware information and save them into a file GenuineTicket.xml. Just copy this file to USB or a second partition or other safe place because you will need it to activate your Windows 10.
- Burn ISO image on a CD and install Windows 10 from the CD. Obviously you can do it from USB. Remember to skip activation: When the installer prompts you for product key, just click Skip button.
- When the system is up locate a folder %ProgramData%\Microsoft\Windows\ClipSVC\GenuineTicket and copy there the file GenuineTicket.xml previously created and saved.
- Restart the PC and enjoy clean installation of the best system in the world.