I am running two anti viruse on one computer.

I am now at home installing some programs that came with my new computer.I install AVG when I first upgraded my PC and decided to purchase some add on thinking that SGD80 pulse is cheap than having to have problems...in the future.After some weeks later I found out that there is a Free trail Norton protection.So to cut things short...guys I am now using two programs together.I hope it will not crash the OS...but things are going fine so far.