Best if you email the support team of the game publisher. Most of us here wouldn't know of the problem unless we experienced it ourselves. And Empire Earth being very old now, unless someone else has the same nostalgic feeling you're having, you'd probably have better luck elsewhere.
On another note, from my experience of playing old games on new rigs just to see how they work out, some old games just die on newer machines and OSes (I see you're on Windows 7). You might have to run a virtual machine running XP or get a dual boot system just to play the game. First thing is to try Compatibility Mode. If that doesn't work then there's a chance it might not work on Windows 7.