How do I prevent update to Windows 10?

My 89 year old mother got forced to do the update to Windows 10 and just two days later, finds that her start button doesn't work and she can't start most of her apps. I expect she will agree to revert to Windows 8.1 and I found some instructions to do that.

What will I need to do once I have her computer back to 8.1 to keep it from updating to Windows 10 until I'm satisfied that Microsoft has *finally* fixed the problem with the Start button?

I've done some googling but only seem to find articles about how to stop doing updates when you already have Windows 10 installed.

Found this here:

The easy way: Install GWX Control Panel, then click some buttons

The simplest way to make sure you won’t accidentally end up with Windows 10 is a program called GWX Control Panel. You can download it free from the Ultimate Outsider website. There’s an install file, and a portable instance of the application.

Or ... Upgrade to Windows 10 Update - Enable or Disable in Windows 7 or 8.1 - Windows 10 blog

I hope you are aware that the easiest and best way to revert to her original 8.1 is go to Settings>>Update & Security>>Recovery>>Rollback.

Thank you for the answers. As it turns out, Windows 10 "fixed itself" somehow. I signed onto my mother's computer to remove Windows 10 and found that the Start button was back and working fine. I'm completely baffled by how this could happen since neither she nor I did anything and no further updates had arrived from Microsoft.

We're going to leave Windows 10 in place for the time being but plan to remove it if it misbehaves again and revert to Windows 8.1 until they've got the bugs out of Windows 10.

I'm glad to hear things worked out. Just remember, the easy rollback feature I recommended is good for only 30 days from the day you downloaded the original Windows 10. FWIW, I originally hated Windows 10 but now use it exclusively and I have several computers to choose from.

I'm glad to hear things worked out. Just remember, the easy rollback feature I recommended is good for only 30 days from the day you downloaded the original Windows 10. FWIW, I originally hated Windows 10 but now use it exclusively and I have several computers to choose from.

My mother and I have nothing against Windows 10 in principle and are willing to keep using it *if it works*. But if you can't launch most of your programs, it is WORSE than useless, it actually inhibits you from doing what you are trying to do. When that happens, we will move on to something else, either temporarily or permanently.

Look at Classic Shell or Start10 as replacements for the Win 10 Start menu.

Look at Classic Shell or Start10 as replacements for the Win 10 Start menu.

Thanks for the suggestions; I didn't realize there were alternatives within Windows 10 (as opposed to reverting to older versions of Windows or an entirely different OS).