The Past Ain't What It Used To Be... The first Command & Conquer received its last official update on the 21st of June, 1996. Since then, the game has been ported to Windows (as "Gold" version), and re-released in the big "The First Decade" collection pack, but has never received any more bug fixes. The C&C Gold Patch 1.06 project aims to bring this classic into the new millennium, by fixing the old bugs, supporting higher resolutions, and adding new modding and mapping possibilities. It also contains an addon-based language system, allowing anyone to create translation packs for the game.
Full overview of all the options available on the new setup tool.
See this article for the complete explanation:
Moddb.com
I recently realized how silly the "original res"/"high res" radio buttons are, sio they're gone now. You can just select from the list of 6 options. The "original res"/"high res" text is still in between them, but they're not options, and all options are simply enabled.