I am not able to open zip files?

Hi friends can anyone one tell me why I am not able to open my zip files. Whenever I try to it ,It try to open through Internet Explorer, for closing it i need to reboot my PC. I also tried to download winzap 12.0 over the net but I am facing the same issue .please tell me with the issue with my PC.

I guess your PC is effected by virus.Please reinstall Windows and put a fresh copy of Anti virus software or download it from the net.