Command & Conquer 1, Red Alert 1 and Tiberian Sun have all been upgraded with community-created unofficial patches that fix a lot of their bugs and compatibility problems. For Red Alert 2 there's a more general patch that solves a lot of its graphics problems.
The patches for C&C1 and RA1 offer full resolution controls, and the cnc-ddraw addon included in them allows stretching the aspect ratio.
Do note that resolutions getting stretched to full screen happens due to properties of your graphics card driver. While this can be remedied through cnc-ddraw by stretching the game to a custom resolution fitting your monitor, you should probably check your graphics configuration to change the default behaviour for lower resolutions.
You can find the patches here:
Command & Conquer 1:
Red Alert 1:
Tiberian Sun:
Red Alert 2:
- The graphics system patch DDWrapper is known to solve a multitude of graphics problems, including the "black screen" issue.
Download the zip file and extract "ddraw.dll" and "aqrit.cfg" into your game folder. Then, open the configuration file "aqrit.cfg" in Notepad, change the "ForceDirectDrawEmulation" option to 1, save the file, and try running the game again.
- If you still have problems with RA2 even after this, I advise installing the CnCNet online play installer for RA2/YR. Even if you're not interested in online play, it comes with a bunch of automatic fixes, and has a configuration tool which offers more choices in graphics fixes than just DDWrapper, so if one doesn't work you can just try if some of the other options do the trick.