calling executable on ASP page using Process.start

I have seen a number of posts (most dating back to 2002 regarding
using System.Diagnostics.Process.Start() from an aspx page to call an
executable on the server - my code does not seem any different from
examples I have seen but I simply cannot get anything to happen
whatever executable I try to call. On a simple aspx page with one
button this is the button click method
the remmed out portions are, as far as I can see just different ways
of doign the same thing. Is it to do with the IIS config perhaps? its
set to allow executables on localhost
private void Button1_Click(object sender, System.EventArgs e)
{
//oP = new System.Diagnostics.Process();
//oP.StartInfo.FileName=@"c:\gwave426";
//oP.Start();
System.Diagnostics.Process.Start("Iexplore.exe");
}

TIA
John Murray