I have recently installed FS2004 on a 1.3G Processor, 1G RAM machine. I have had problems with the ATC sounds - either AI or "real" (via vatsim). Whenever I use AI ATC, the dialogue is very slow. It sounds as if you are playing a tape at super slow speed. The same holds true when I connect to Vatsim and use SBRelay and voice. I tried using EndItAll, and closing all but essential programs but that did not help.
Noble Air LAX Hub AHC