I'm sorry I wanted to write them and forgot🤦🏻♂️
Core i3
Gts 250
4 Ram
This is incomplete and not very specific. Exact RAM model and how many sticks. And what's the exact i3? After all, those have been made for more than a decade now. Motherboard? Power supply?
The only thing I know for sure about your PC is that you have a non-gaming GPU from 2009. That shouldn't game very well at all, but you're asking about specific games without actually saying the specific games. And what were the exact framerates of these games before? Have you installed the drivers? What else have you done to diagnose this problem?
There's just a lot of information missing. None of us can see your PC; you have to be our eyes and ears and you haven't told us very much.