Posted May 06, 2015
H3RB3RTW3ST: I've done that. It checks itself back. That's why I'm so puzzled. I have admin privileges too. I'm just baffled.
Zogundar: This comes a tad late almost 2 1/2 years later, but I was having the same issue and after a great deal of searching discovered the problem. There's a registry entry that's responsible for this.
(As always, beware editing the registry, you can destroy Windows, etc.)
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\Layers\C:\(Install Directory)\(Game Directory)\KODP.exe
By default it's set to "640X480 DISABLETHEMES DISABLECICERO DISABLEDWM HIGHDPIAWARE RUNASADMIN"
I deleted everything except "RUNASADMIN." After this, I was able to make changes to the Compatibility section and make them stick.
Combined with jerfa's post in this thread I'm now able to play the game, windowed, without having to manually change the screen resolution afterward.
Thanks!