KPG38 and all my other Kenwood software works fine on WIN10. Just did a few updates to TK290s and TK390s a few weeks ago.
Have tried most on WIN11 and the all work, but haven't tried KPG38 on this system.
Kind have stay with WIN10 for now, since my older cable won't work in WIN11, but works fine on all TK290/390 and TK5210/TK5310 in WiN10.
As long as it's working I am too cheap to purchase a new cable just to use WiN11.
Computer used to to program in WIN10 is kind of basic, but works great for what I am doing, plus it's a smaller computer so easy to take on my delivery over night work trips.