process proc = new process();
proc.startinfo.filename = "cmd.exe";
proc.startinfo.useshellEXECute = false;
proc.startinfo.redirectstandardinput = true;
proc.startinfo.redirectstandardoutput = true;
proc.start();
proc.standardinput.writeline("dir");
proc.standardinput.writeline("exit");
string line = null;
line = proc.standardoutput.readline();
while (line != null)
{
richtextbox1.appendtext(line);
richtextbox1.appendtext("\n");
line = proc.standardoutput.readline();
}