Installing Drivers - New Windows (Beginner)

Here is my hardware
Processor: Intel (R) Core 2 Duo CPU E7400 @ 2.80 Ghz @ .79 Ghz
RAM: 2 GB
Windows 7 sp1 32-bit system
Vidyuha NVIDIA GeForce 9600 GT

In general, I reinstalled windows. Before that there was a seven sp 1 Skyrim. Max Payne 3 walked, did not lag. Then Total war rome 2 downloaded noticeable braking (especially when there are a lot of troops). On low grails, too, the same, but something more or less.
I decided to reinstall Windows myself, I think all the formatted computers of the International Federation of Journalists are already hammered, I installed windows 7 sp 1.
Without programs, after installation, the indicator shows that the CPU is 30-40% loaded and the RAM is 50-60%
The question is, is this iron weak? (BUT above I said that in Skyrim and max payne 3 I played without lags on the seven) Or do you need firewood?
I did not install anything after I downloaded Windows, the computer is clean. Windows 7 sp 1