2.3 is a little more resource-intensive than 2.2.x from my experience, and Vista is a resource hog of an operating system, which can cause UFO: AI to sometimes run slow - fortunately there are ways to turn off many of the unnecessary and ridiculous services:
- Turn off Areo.
- Turn off themes and run in "basic" mode.
- If you can find the advanced settings under control panel, change performance from all the eye-candy to "adjust for best performance."
Research on the internet can also provide other hints - these are just off the top of my head.
Also, what video card drivers do you use? The ones you get from Windows Update, or direct from the manufacturer? That also makes a big difference. (The latter choice is much better.)
Aside from that, if we're going to give any real help though, we'll at least need some system specs.
