I'm running BTS in Win 7 RC with no problems so far. Well...kind of..I'm also running BAT 2.0 mod w/BUG 4.1 upgrade. I have 4 GB memory (OS only uses 3.5 GB due to it being 32 bit) and have a ATI 4870 w/1GB memory. My proc is an E6400 tweaked to 3.2 GHz. The only problem I've run into is the Memory Allocation Failure (MAF). The research I've done shows that its partially due to the huge maps I'm running, memory leaks in the game, and running my graphic settings at full tillt ahead. My saves are ~1200k which is almost double the standard save I believe. What this means is that about mid-game my 11 Civ, Fractal, Marathon game has to be rebooted approx. 24 mins. If I wanted to tone down my graphics I probably won't have as much a problem but I like the eye candy.