UT99 server is running
this should work if you have an AMD processor.
If not, once you have Unreal running, hit CTRL ALT DEL and go the task list, processes tab. In there, find unreal.exe, right click and go to "set affinity" then select it to run on only one of the two cores. Unfortunately if you do it this way you have to do it like that manually every time you run the game....