I keep getting a issue that crashes my game and says "display driver stopped responding and has recovered "

Here is the story....

So I play cs go a lot, it doesnt do it everyday but it has being doing it a lot recently, it does it in other games as well, it freezes my game then all sort of colours will appear, I will either have to restart PC to get rid of it, or just ALT+CONTROL+DEL then start task manager and close the game and then my screen goes black I move my mouse and it brings back my desktop and says at the bottom right "display driver stopped responding and has recovered "

A week before I started getting this issue, I got mad, really really mad, so mad that I opened up my PC took out the ram, graphics card and motherboard and threw it out the window, also my monitor. Then the next day I tried putting it back together I did it all wrong and **** up the motherboard I think as I put things in wrong places, so then I gave it to a PC expert, I had my old motherboard from my old PC and he put it all back together. So currently I have the same RAM, CPU and GPU that I threw out the window, it worked for a while then I started getting these "display driver stopped responding and has recovered" with my screen all sorts of colours.

So right now I am wondering what parts do I need to get, or is it not even the parts could there be a virus or something on my PC, I have read all sorts of things that might cause this issue I just need some help!

I have a asus gtx 550 ti [ Register or Signin to view external links. ]
4gb Ram
AMD Phenom II X4 965 3.40GHz