Guide: Using XCC RA2 Map Updater
You will need XCC RA2 Map Updater and Command & Conquer: Red Alert 2.
You can download the XCC utilities from http://xhp.xwis.net/.
This utility retrieves all map packs released by Westwood Studios before it launches Red Alert 2. This means you can simply start this utility instead of RA2 and you'll automatically get all map packs as soon as they're released.