[Sinistra]

I don't know if it helps for everyone but for me it worked.

I have windows 8.1 and when I started game in compatibility mode with Windows 98/Windows ME option it worked good when using full screen.

Step by step instruction

Go to place where you've got your game installed and find Ranger.exe, mostly common used
C:\Program Files\Steam\SteamApps\common\Space Rangers\Ranger.exe
It can be somewhere else if you changed destination folder when installing Steam or your game.
Left click Ranger.exe -> Properties -> Compatibility -> Check box for Compatibility mode -> Choose Windows 98/Windows ME
Start game and enjoy.

You can try other compatibility modes but this worked for me.

One last information it works for Space Rangers 1 and 2 Reboot in my case.