How to create a process as Admin in my windows service program?

ProcessStartInfo processStartInfo = new ProcessStartInfo
                                        { FileName = "calc.exe" };

if (Environment.OSVersion.Version.Major >= 6)
    processStartInfo.Verb = "runas"; // Windows Server 2008, Vista or higher;
                                     // User will be prompted

processStartInfo.Arguments = "";
processStartInfo.WindowStyle = ProcessWindowStyle.Normal;
processStartInfo.UseShellExecute = true;

Process process = null;
try
{
    process = Process.Start(processStartInfo);
}
catch (Exception ex)
{
    // Exception handling here
}
finally
{
    if (process != null)
        process.Dispose();
}