I didn't make it!
Your 3GHz Pentium 4 chip uses Hyper-Threading technology to act as dual processors. JK2 version 1.02a won't run on "multi-processor" machines, you need to patch to version 1.03 or 1.04.
Q: I cannot get Star Wars Jedi Knight II: Jedi Outcast to work on my system with dual processors.
A: You need to install the latest patches (1.03 or 1.04) in order to make the game compatible with dual-processor or Hyper-threading systems.