I recently upgrade my Windows 7 from 32 to 64 bit. I did this because I wanted to add more RAM, which is at 4 GB now.
Prior to upgrading, my games ran smoothly without any hitch. But after getting 64-bit, my games stutter every once in a while (everything slows down, including framerate). There is no effect on my GPU temp. This occurs even when I lower resolution and graphic settings, as well as when I turn on or off V-Sync.
Do you have a bunch of 32-bit programs running on the background or something? In a 64-bit OS, a 32-bit program will essentially use twice as much RAM when requesting memory to store variables, ie it will get a 64-bit block for every 32-bit block it requests. You can really see this effect with some 32-bit virus scanners like.
as megamanx00 said, under 64 bit the 32 bit programs will use more memory. Beside that, Win64 will "enjoy" more memory if it has it available, in my experience 4Gb is kind of a minimum that a 64bit installation will need to run properly. If you want to run games smoothly, I would recommend doubling that up. Memory kits are pretty cheap nowadays and you will notice the benefits immediately.
Also, keep in mind that from the very summarized specs that you published above, i can see that your video card could be the bottleneck as it is an aging model. Also, addressing the HDD could be more frequent under the 64 bit OS given that the amount of memory is kinda low. That could explain the stuttering experienced in your gaming sessions as well.
If I were you, I would consider doubling the memory> upgrading the video card> replacing the HDD. It could be that the HDD is approaching it's end-of-life, especially if it's of the same age as the rest of the system.
Hope it works well one way or the other.
i resolved my problem. because my problem did not result from the GPU temps and my RAM was fine, i knew it had to be the CPU. Removed heat-sink, cleaned, reapplied thermal paste. Voila, problem is gone and games work swimmingly.
I had the same issue, turned out to be my NVidia driver....I had to revert to version 306.97. My problem is now fixed 100%.... btw if you try this, turn off windows automatically being able to install updates your computer, it will keep installing the newest one. I made it so I choose the updates I want installed and I don't let it update my NVidia driver, and now all runs sweet!