Process started by Process.start() returns incorrect process ID?

Question

I am starting an executable using this code:

Process proc = new Process(); proc.StartInfo.FileName = executablePath; proc.Start(); proc.WaitForInputIdle(); 

after this calling proc.Id it gives me some integer, which is not real process ID. In the task manager there is another ID for this process and also I am using MS UI Automation to access this application, which also returns the same ID as in task manager. So my question is how can I get the real process ID of started process?

UPDATE

I found out that on Windows 7 it works fine and returns me the right ID, but not on Windows XP. What can be the reason?

SCENARIO

The scenario of the application is the following. I have a running embedded HTTP server, which is implemented not by me, (here is the source). The client connects to the web server and sends a request to run a program. In the request handler of my server I am just using Process.start() to start the requested application. As a web server the program creates threads for every client session connected to it (I assume so, as I didn't wrote it). Can this somehow help to identify the problem as it exists only on Windows XP X86 Service Pack 3?

Answer 1

An example of how I did it:

    bool started = false;     var p = new Process();      p.StartInfo.FileName = "notepad.exe";      started = p.Start();      try {       var procId = p.Id;       Console.WriteLine("ID: " + procId);     }     catch(InvalidOperationException)     {         started = false;     }     catch(Exception ex)     {         started = false;     } 

Otherwise, try using handles like this:
Using handlers
Getting handler

hWnd = (int) process.MainWindowHandle; int processId; GetWindowThreadProcessId(hWnd, out processId);  [DllImport("user32")] static extern int GetWindowThreadProcessId(IntPtr hWnd, out int processId); 

Side note:
What happens if you get the array of process and iterate over them and compare the PIDs?

Process[] p = Process.GetProcessesByName( "testprogram" ); foreach(var proc in p)     Console.WriteLine("Found: "+proc.Id == myExpectedProcId);