I found that by installing CFS1 on an old computer running Win 8.1 and then copying the installation folder located in Program Files (x86) under Microsoft Games, I could copy the Microsoft Games folder with the installed Combat Flight Simulator folder inside of it and paste it into my Win 11 hard drive Program Files (x86). Works fine on my setup. In addition, you will need to enable Direct Play on your machine and also paste a copy of the combatfs.exe file into the Windows folder on C: drive. Basically, install on an older machine and then cut and paste into the newer machine. Still requires original disc to start up each time as in the past.