Windows 10: get stuck in 48% during installation win 11 upgrade from win 10

I got an offer to upgrade to windows 11 on windows update. and I have also checked "PC Health Check" where I got the information "this PC meets windows 11 requirement". I finally decided to "download and install". everything work smoothly until 48% of the installation process and after that the screen went black and couldn't do anything. after a few hours still nothing i can do. I decided to click the power button which finally appeared "undoing change made to your computer..." after that it returned to windows 10. now the download and install buttons no longer appear, only the notification "t

:)