How to Setup Prerequisites

Hi

I have developed one .Net Desktop Application now i need to setup that project Setup file should be Single Icon and single Click when i click that Setup icon it needs to install my application on target System, Before install my application setup needs to check whether prerequisites(.NetFrameWork and DirectX) installed or not if not it needs to download and install prerequisites after that main application should install on target system. How to check which DirectX version installed on target system from my application

anybody can helpme?