Can I install Windows 11 and Windows 10 on separate hard drives with the same activation key?

Question

If I upgrade my primary drive to Windows 11 using the free upgrade option, can my secondary drive (which is a clone of my primary hard drive) still run Windows 10 with the same Windows License/Key?

Long story short, I ran into a lot of issues converting my primary hard drive to GPT/GUID, so I'm very nervous that upgrading to Windows 11 may make my hard drive unrecoverable. I currently have 2 cloned hard drives (one MBR and one GPT/GUID) stably running windows 10 with the same activation key for both on my PC. This activation key is saying that I can upgrade to windows 11 for free now. Can I upgrade to Windows 11 on the GPT/GUID hard drive, while still keeping Windows 10 on the MBR hard drive, and do that while using the same activation key for both? Thanks for your help!

Answer 1

When you upgrade to Windows 11 using the free upgrade option, the Windows 10 license that was previously associated with your PC will become associated with the new Windows 11 installation.

Most Windows 10 and Windows 11 licenses are now tied to your hardware (specifically the motherboard) via a digital license.

Microsoft's licensing terms generally allow you to have only one active installation per license. So, it won't allow you to run two different versions of Windows (e.g., Windows 10 and Windows 11) simultaneously on the same license, even if it's on the same hardware.

The safest approach would be to use separate licenses for each installation if you plan to keep both active.