It runs on windows 7 but you'll probably get a problem with the colours in the game. You can fix that by shutting down windows explorer every time you play
There's an app floating around somewhere on the interwebs that auto-shuts explorer when you start AoC and auto-starts it when you close AoC, which is handy for that. Can't remember where I got it, but it's in my download folder if anyone really wants it.
Also, apparently gameranger does that automatically.
If anyone's interested I've made a scenario based on a normal game, but instead it's with heroes instead of normal units. Each civilization has its own basic heroes (Charlemagne, Scythian Scout etc.) apart from Aztecs and mayans which don't get horses. You use your 'Shah' unit (a hero king) to buy things with that are available in different ages with different things built. You can create units at any of the locations on the map. It's also got a regicide-type twist meaning if you lose your Shah then you die