Noticed you are running direct-X 9 you might want to check to make sure C&C 3 doesnt require direct-x 10.
Go to your sys.information page and do a direct 3D test to see if it passes.if you know how i apologize in advance,if not go her start,all programs,asseccories,system tools,system iformation and clik.then clik on the tools tab and drop down to direct x diagnostic.open and wait for all sigs. to load.( bottom left)then test your direct draw and direct 3-D to see if they pass.
if so I sugest you check you virtual mem. on system info. main page and make sure you have at least 2 gigs and almost all that avalible. If this all looks good you probably need direct x10 because its the direct 3-D that is the initial error
Try start ,run,type msconfig and enter.go to start up and disable all then restart with this selective start up and nothing will run in the background to use up any mem.
but it sounds like a new game that may need 10