Print PDF with ASP.NET and Acrobat Reader

I have a web application on a server with Windows Server 2008 R2 and I’ll print a file pdf (on server-side).

• Printers are shared printers, physically connected to another server (Windows Server 2008 R2)
• The website have an Application Pool Identity and the virtual account (DomainName\NameComputer$) have full permissions on printers.
• ‘IIS APPPOOL\NameAP’ have full control on Acrobat Reader (AcroRd32.exe)
• Everyone group can print, manage printer and document on the shared network printer.
• Everyone group have full control on process AcroRd32.exe

I use Process class with this code:

ProcessStartInfo infoPrintPdf = new ProcessStartInfo();
infoPrintPdf.FileName = pathPdf;
string printerName = "\\namePC\namePrinter";
infoPrintPdf.FileName = "...\AcroRd32.exe";
infoPrintPdf.Arguments = string.Format("/t {0} \"{1}\"", 
  pathPdf, printerName);
infoPrintPdf.CreateNoWindow = true;
infoPrintPdf.UseShellExecute = false;
infoPrintPdf.WindowStyle = ProcessWindowStyle.Hidden;
Process printPdf = new Process();
printPdf.StartInfo = infoPrintPdf;
printPdf.Start();
printPdf.WaitForExit();
printPdf.Close();

Process AcroRd32.exe remains in running state and don’t print. Any idea?

I try to open file pdf on server and doesn't work. An extract:

Process.Start(@"...\Print.pdf");

The process AcroRd32.exe is in running with username ‘IIS APPPOOL\NameAP’. With Visual Studio in debug this code works.