The story is a little longer :
- upgrade from Windows 8.1 to Windows 10 - everything ok
- used for a while with Windows 10, in good conditions
- changed user, which wanted to reinstall Windows
Reinstalled windows from scratch, using original Windows 8.1 installation DVD ; installation was ok, but Windows didn't recognized the authenticity of the software and ask for a valid key. The OS is OEM, so we don't have any key for Windows.
Please help us to get Windows activated.
Regards,
George Dumitrescu