Here you will find various ISO images of retro things, e.g. things that run under Windows XP, which amuse me. You may need to decompress the zip file, write the CD or DVD and run it under VM Workstation, but licences are dirt cheap on eBay (a couple of pounds).

1. Enemy Nations. Runs under Windows XP Only!
   A "simple" colonize and dominate the planet game. Build infrastructure, smite rivals, and destroy them to win. Oddly addictive...
   Download