This is very helpful information. Thanks. However, I am still having issues running US4 Mona... Apache unable to start due to port 80 is being used. I know full well that I don't run IIS, Skype or any other apps that would used port 80. For now I am staying with 3.5 and has been for over 8 m without any issues. I was wondering if anyone here have solutions on running Mona on Vista Ultimate 64x? Thanks again. Uniform Server ROCK!! Many thanks to the developers for the hard work.