How to detect whether Java runtime is installed or not

Question

I program windows applications using Java and this builds a ".jar" file not an ".exe" file. When a client computer with no java runtime installed opens the ".jar" file, it runs as an archive with winrar. All I want to know is how to detect whether java runtime is installed or not on a computer using c# code in order to show a MessageBox telling user to install java runtime, or launches the ".jar" file using the java runtime if it's installed.

Answer 1

You can check the registry

RegistryKey rk = Registry.LocalMachine;
RegistryKey subKey = rk.OpenSubKey("SOFTWARE\\JavaSoft\\Java Runtime Environment");

string currentVerion = subKey.GetValue("CurrentVersion").ToString();