You won't find a driver for your CPU, it doesn't need one. What you should be looking for is the drivers for your motherboard and other hardware. For the motherboard the primary driver needed is the chip-set driver. After that, drivers for any onboard sound, video, network etc. I'd start by going to the motherboard manufacturers web site and look up your particular make model. After that you do the same for any add-in cards like Video etc. The big thing is to know exactly what you have in your PC. Just make a list and save it as a text file for reference. Programs like Speccy - System Information - Free Download
- can give most if not all the info you need to figure out what you have.