Same way you install any other game I have them all running under win 7 ???
But the only thing you need to do is alway run them as the Admistrator as you need to have full file access
All of my versions installed on 64bit Windows 7 and are perfect. It is nice to check my older models which didnt make it into builds and upgrade to make them available to later versions.
Another reason is speed. On my old computer with XP it took over 5 minutes to re-build the chache files on TRS2004. On my new computer running Windows 7 Ultimate it only takes 5 or 6 seconds. Yes the new computer is faster but the speed increase isn't only due to it.