Just avoid Program Files (x86) ,,,,
To expand on this a bit...
You can avoid a number of issues/annoyances (in particular, with modding, but also with save games being difficult to find) by installing to somewhere other than C:\Program Files or C:\Program Files (x86). For example, C:\Civilization III, C:\Games\Civilization III, or if you have a second hard drive, D:\Civilization III.
The reason is that this sidesteps a feature of Vista, 7, and 8 that makes it difficult to modify files in C:\Program Files and C:\Program Files (x86), as well as a few other locations such as C:\Windows. That feature does theoretically increase security, as it makes it harder for malicious software to change files in those areas, which is where most programs are installed. However it also results in it being a lot more difficult for regular people to intentionally change the files here (be it for modding, finding save games, or something else). So, for older programs including Civ3, it can be a lot easier to just install it somewhere else and not deal with the hassle.
Whether Civ3 plays fine when installed in the default location on Vista/7 seems to vary somewhat. But if you ever do anything mod-related, you want to be sure it is
not installed in the default location.
(I can't help with many more particulars, as I switched back to XP half a decade ago. But I'm sure others can)
robbus said:
CIVIIassist is not currently working in win7 though. I have managed to install it but when it runs anerror occurs.
What's the error? I've heard it's possible to get CAII working in Win7, at least most of the time. Puppeteer's
video demo here is reported to be helpful in getting it installed/working when it's initially problematic, though being on XP I haven't tried it myself.