I have a HP Pavilion Entertainment Laptop PC
Windows Vista Home Premium
Service Pack 2
Intel(R) Core(TM)2 Duo CPU P8600 @ 2.40GHz
6.00 GB RAM
NVIDIA GeForce 9600M GT
64 - bit
This sounds like my machine.
I have the HP Pavillion dv7t, also with the P8600 and the GeForce 9600M GT. I have 3Gb of RAM.
I'm running Windows Vista Home Premium 32-bit.
I can run the game just fine, albeit with no more than 12-14 FPS.
Some things I did to boost performance...
1. I overclocked the video card to the max. After doing a lot of internet research on the video card, this card can take overclocking without overheating. I used the EVGA Precision overclocking tool. My overclock settings are: core clock 600 mhz, shader clock 1500, memory clock 480.
2. The HP Pavillion initially warned me not to upgrade the NVidia card to the latest version because it was not the OEM driver that came with the laptop. After a few years, though, I decided this didn't matter anymore, and upgraded to the latest NVidia drivers.
3. I turned off antialiasing within the game, and set the controls directly from the NVidia drivers. I have everything else to the max, except for turning off reflections and transluscent?
4. The HP dv7t from a few years ago (with the P8600) was notoriously poor at heat dissipation. My laptop would shut off randomly when running at max speeds. I finally tracked this down to CPU overheating (and SSE runs the PC at the max capacity). I needed to undervolt the laptop in order to keep the CPU temps low enough to sustain high performance indefinitely. I use the RMClock utility to do this.
5. I also run Game Booster from Iobit to stop most background processes. In fact, I also use the Task Manager to set Questviewer to High priority once the launcher starts is. I don't think that launching Steam with High priority will cause Questviewer to also launch at High priority, so I launch Steam normally and then boost Questviewer to High.
I don't think that this is directly responding to your problems, but I added to the thread to show you that your machine is capable of running SSE.
Have you tried uninstalling and reinstalling?
Steve