Running C Compiled Executable File In Java

I'm trying to run a command line executable file using java but there is no output. On the task manager a conhost process opens when the application is run. I've tried

1)try {
Runtime.getRuntime().exec("D: est.exe");
} catch (Exception e) {
e.printStackTrace();
}

2)String[] cmd = { "D: est.exe"};
Process p = Runtime.getRuntime().exec(cmd);
p.waitFor();

and

3)//Runtime.getRuntime().exec("D: est.exe", null, new File("D:"));

same thing happens i.e. nothing happens.