Why does silent hill 2 suck on my kick-*** computer?!?

I have an awesome new dual-core computer, a Dell Vostro 3500 laptop w/ 2 core i5's @ 2.66 GHz. My video card is an NVIDIA GeForce 310M that has 512 MB of dedicated vRAM, 4GB RAM, and NVIDIA High Definition Audio (I'm assuming that's my sound card). I applied the sound looping patch, but that seemed to work to an extent. I also applied that NVIDIA GeForce patch that was supposed to fix something with the video but I'm not sure what it fixed. I also tried setting the affinity for the program, but then the game goes super slow! I read in the task manager, when I set the affinity to one core (My computer has 4 logical cores), the game takes up exactly 25% of my computer. When I set it to 2 cores, it runs at 50%, and so forth. the game takes up 75%-80% of my computer, and my pc starts to overheat after a while. I don't understand... I'm also running windows 7 Professional. For some reason, this age-old video game is eating up all of my processing power! How did they even run this game back when it was released?! Can someone please tell me what I did wrong?