Windows 11 has very restrictive hardware requirements . These requitements are not really necessary for best performance but to encourage the use of new security features on newer hardware. As I demonstrated back in July, Windows 11 runs great on older hardware.
Download the Insider build and create a bootable USB stick with it using Rufus or your favorite program.
Boot to the USB stick, at the prompt “select a language” and click next. At the prompt click “Install now”. You will probably come to a prompt that says “This PC can’t run Windows 11.” Press down “Shift + F10”, this will open the “Command Prompt”. Enter “regedit” and hit the” enter key.” This will open the ‘Registry Editor.’ Go to HKEY\LOCAL_MACHINE\SYSTEM\SETUP. Right-click SETUP and go to NEW\KEY to create a new key. Name the key LabConfig. Right-click inside the box to the right and goto NEW\DWORD (32-bit) Value, name it BypassTPMCheck. Double-click the DWORD and enter 1 as the Value. If your computer does not have the minimum 4Gigs of RAM you will have to create an entry for that. BypassRAMCheck and if you don’t have “Secure Boot” create a DWORD labeled BypassSecureBootCheck. The Value of all of the Keys are 1. Exit Regedit, the Command Prompt, and the warning screen. Click “Install now”, then follow the prompts.