java: call external jar program (-> 'create process error')

i'm trying open/execute another program of me, which is a (.jar) file,

but i'm gettin the error that 'it is not a windows application'

(java.io.IOException: CreateProcess error=193)

here is my code:

import java.io.IOException;

public class Test8 {

    public static void main(String[] args) {

        try {

            String filepath = "C://Users//Alex//Desktop//Speedtest.jar";

            Process p = Runtime.getRuntime().exec(filepath);

        } catch (IOException e) {

            e.printStackTrace();
        }

    }

}