If your RA2 gameplay is very laggy in modern versions of Windows just add the following lines to your RA2.ini
The RA2.ini file is located in the games installation directory, edit it with notepad
Find the video section and add VideoBackBuffer=no, you can also take the opportunity to set a larger screen resolution if you play on a big screen!
[Video] ScreenWidth=1920 ScreenHeight=1080 StretchMovies=no VideoBackBuffer=no