1st of all you assume wrong , Windows 10 will still not play old games like star trek battles because the background OS is different and no patches ever came out to fix the sniffer returning faulse
2nd your path the Windows 10 is the same as its always been, goto the Microsoft store and follow the promps... yes its a bad in the ass but once you upgrade your key then the new installs can go dirrect to Windows 10 next time
p.s, you are going to really hate W11 in 3 years time if you see W10 as having issues with old games because w11 has issues with current games as well