Heather, As Neilpzz indicated, it’s been well covered in this thread. On December 21st 2024, I wrote a long response to how to fix the issue. You need to go to that write up and read it over. There are multiple other responses to this as well. You have to go that Microsoft website, download the Windows 11 24H2 ISO file and burn it to a disk or put it on a thumb drive. Once you do that, boot up and press F8 a few times when you see the BIOS/UEFI setup screen. That should take you to the BOOT disk options and you’ll need to select whatever disk you has the new Windows 11 24H2 system on it. Once it starts booting up from the thumb drive or DVD disk you made, you should see a screen that says Install Windows 11 or Repair Windows 11. I found that the repair option on that screen doesn’t help much but who knows? It may work for you. The best option is just select install Windows 11 and answer the questions on the following screens and hit NEXT after each one.
The biggest thing you need to do before you get started is back up all the files and documents you want to keep. That’s a must anytime you’re making major changes to your computer.
I don’t want to repeat the entire response that I already wrote but as I stated already, go to the December 21st response and read that over as well as many other individual’s responses.
Hope this helps and Have a wonderful New Years. 🥳