Why Process.Start doesn't work from asp.net web service?

Question

Why this code runs perfectly on my development computer (win7 32bit) and on target server(2008r2 64bit) as console app. But when I try to run it as a web service on the target server it does nothing. No error, nothing.

If I remove

exitMsg = proc.StandardOutput.ReadToEnd();

then it fail with error:

System.InvalidOperationException: Process must exit before requested information can be determined.

   [WebMethod]
    public string GetRunningProcesses()
    {
        ProcessStartInfo pInfo = new ProcessStartInfo();
        pInfo.FileName = @"E:\bin\PsList.exe";        
        pInfo.WindowStyle = ProcessWindowStyle.Hidden;
        pInfo.CreateNoWindow = true;
        pInfo.UseShellExecute = false;
        pInfo.RedirectStandardOutput = true;

        string exitMsg = "";
        int exitCode = 1;

        using (Process proc = Process.Start(pInfo))
        {
            exitMsg = proc.StandardOutput.ReadToEnd();
            proc.WaitForExit(1000);
            exitCode = proc.ExitCode;
        }

        return exitMsg;
    }

I think there must be something about user under which code runs. As web service this code runs under asp.net user and this might couses the problems.

Please advice me how to fix this. Thank you very much.

RESOLVED

---

The problem was with EULA dialog, which poped up but it was invisble due to ProcessStartInfo settings. When I run PsList.exe via CMD under account which is also used for Application pool for this web service, I get prompted for an EULA agreement and after that everthing works fine.

The strange thing is that I have "pInfo.Arguments = "/accepteula";" in my real code. This should prevent my probem, but it didn't and I don't know why. If any of you knows why, please tell me.

Thank you very much for all the help. You are trully good peoples here.

Answer 1

The problem was with EULA dialog, which poped up but it was invisble due to ProcessStartInfo settings. When I run PsList.exe via CMD under account which is also used for Application pool for this web service, I get prompted for an EULA agreement and after that everthing works fine.

The strange thing is that I have "pInfo.Arguments = "/accepteula";" in my real code. This should prevent my probem, but it didn't and I don't know why. If any of you knows why, please tell me.

Thank you very much for all the help. You are trully good peoples here.