Dude, you won't be able to play the game even if you do get it to install. You should think about upgrading first.
It's because I thought your name was omen for some reason.
I just read through this thread, odd that my name comes up without my having even participated. LOL
Anyways, hope I can play GTA IV, but it's not looking too good at this point. I will give it a go none the less because my single core rig has been able to run other games that claim you need a dual core for minimum spec, like Stranglehold and Assassin's Creed. If you have to do things like blow up choppers with RPGs though, it's no doubt going to be a slide show in places.