Plutonium

So i downloaded everything, and BO2 was working. I was cleaning up my computer and started deleting stuff and tried to make it all in one folder and then when i did it, BO2 didnt wanna work anymore. Just giving me a black screen, now that i downloaded MW3 it runs but im havin an issue on hooking up my controller which i will probably fix by the time i write this post, i just wanna know if i should delete everything i downloaded from you guys and re install it or what