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

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();