As of this writing, the only sites I see selling retail editions of Windows 11 are scammy product key websites that I wouldn't trust with my credit card info, so I would recommend buying a Windows 10 license from a reputable site. If you're installing Windows 11 on a new PC you've just built yourself, officially, you should buy a Windows 10 or Windows 11 license. So if you're running Windows 10 Home or Pro on your PC, regardless of whether your PC is officially supported or not, you'll be able to install and activate the equivalent edition of Windows 11. Windows 11 is a free upgrade to Windows 10. Finally, you can just download an ISO file directly from Microsoft’s site. You can also burn the ISO to a DVD, but installing from any USB drive, even an old USB 2.0 drive, will be much faster, so you shouldn’t do that. Once you have a USB drive, you can either boot from it to perform a clean install or run the Setup app from within Windows 10 to do a normal upgrade install. The second is to use the Windows 11 Media Creation Tool, which automates the process of creating a bootable USB install drive or downloading an install ISO file. One is to use the Installation Assistant app, which you install on your PC to trigger a normal upgrade install via Windows Update. Microsoft offers several ways to download Windows 11 manually.

But because Microsoft is rolling out Windows 11 slowly over the course of many months, your PC may not see it yet. The easiest way to get Windows 11 is by checking Windows Update on a supported, fully up-to-date Windows 10 PC.

Should I go through with an unsupported install anyway?.

What are the risks of running Windows 11 on an unsupported PC?.

Installing on a PC without a 64-bit CPU.

Installing on a PC without Secure Boot or a TPM.

Installing on a PC with Secure Boot and any kind of TPM.

What does my PC need to be “supported”?.

I've had Windows 11 running on PCs as old as a Dell Inspiron 530 from 2008, and while I'm not saying this is something you should do, it is something that you can do. This includes advice and some step-by-step instructions for turning on officially required features like your TPM and Secure Boot, as well as official and unofficial ways to skirt the system-requirement checks on unsupported PCs. We've pulled together all kinds of resources to create a comprehensive install guide to upgrading to Windows 11. Or maybe you'd like to install Windows 11 on an 'unsupported' PC because Microsoft is not your parent and therefore cannot tell you what to do. But you may want to install the operating system anyway because you want to test it or because you like to run the newest thing.

We think most people should wait a few months to give Microsoft time to iron out Windows 11's biggest new-operating-system bugs and finish releasing updates for Windows' built-in apps.

Further Reading Windows 11: The Ars Technica review

Windows can only be installed to gpt