And the sounds the machine guns make...
I have an XBOX, which is essentially a P3 with a better design suited for game graphics, and I think the games I play on that look pretty good, but my PC, a P4 with NVIDIA GeForce 4, has a much better environment to play these games, much more control over the controls.
Time to upgrade!
I don't know a good war game for that speed computer but Prairie Dog Hunt Pro (Will open in window.) is a free download. Supposedly this is shareware, but I can't find a register button, it does not have any 'crippled' features, and it hasn't come up with a nag screen after an hour or so play.
I've blasted quite a few virtual prairie poodles with it. Lots of fun, should run on an older machine.