Launching a hidden process as a different user.

I can't seem to launch a process as a different user and hide the
window as well. If i don't specify the user, my window launches
hidden. But when I specify a user, the executable.exe process
launches an empty dos prompt. How can i hide this window?

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System.Diagnost ics.ProcessStar tInfo tempProcess = new
ProcessStartInf o("executable.e xe", parameters);

tempProcess.Use rName = "username";
tempProcess.Dom ain = "domain";
System.Security .SecureString password = new
System.Security .SecureString() ;
foreach (char temp in encryption.getV al("password"). ToCharArray())
{
password.Append Char(temp);
}
tempProcess.Pas sword = password;

tempProcess.Use ShellExecute = false;
tempProcess.Cre ateNoWindow = true;
tempProcess.Win dowStyle = ProcessWindowSt yle.Hidden;

System.Diagnost ics.Process handle = Process.Start(t empProcess);