Dozens of Windows Mobile 6.5 Beta ROMs are floating around the tubes, collected, tweaked and prepared for your use by the kindly souls over at XDA Developers, from whom I’ve adapted this How To.

It's still possible to install Windows 11 with a local account, if you're willing to jump through a few hoops to do it.

Windows 11 is available to download as an .ISO file. You might want a drink before you start, though.