The programmers that made C&C didn't put any cheats into their game. They felt it would be better for people not to cheat. Apparently, however, something happens when you type 'C&C - FUNPARK' to start the game, might be worth a try!

You are apparently able to take advantage of a glitch in C&C.To do it, build a gun turret. Click sell and sell it. While it is going into the ground right click then left click on the gun turret then press S. This stops the selling. Why is this good you ask? 3 minnigunners march out as if the turret was sold so you get unlimited free men. This also works with sam sites, advance guard towers and oblisk towers. Thanks to Justin for providing me with this info!

Here is another glitch: When you have sold one guardtower and pushed the "s" button you can sell the minigunners like this:

1. Build a sandbag wall.
2. Put your minigunners above the wall.
3. Push the sell button and sell the minigunners.