You can now get Empire Earth Gold Edition for free from Good Old Games. Its their holiday giveaway this year. For those who don't know, GOG sells DRM-free games. Most of their catalog is classic old games like the original Neverwinter, Fallout, etc updated to allow for use on modern Windows OS (even 64-bit), but they also have the Witcher series.
All you need to do is sign up for an account and go here
. There's a holiday sale going on too, so check that out as well.
Edit: The promotion ends in 48 hours, but the sale goes on for two weeks.