CommPortIdentifier.getPortIdentifiers is empty

I am creating a simple application that communicates via a serial port using the Java Communication API javax.comm.

Here is some code in my main java method that I wrote:

CommPortIdentifier cpi = null;
        Enumeration e = CommPortIdentifier.getPortIdentifiers();
        while (e.hasMoreElements()) {
            try {
                cpi = (CommPortIdentifier) e.nextElement();
            } catch (NoSuchElementException n) {

            }
            System.out.println(cpi.getName());
        }

Listing e is always empty, even if I am connected to the COM port when doing this.

also by running this code:

portRead = CommPortIdentifier.getPortIdentifier("COM8");

trigger a throw NoSuchPortException

I think I did the part of the installation correctly and placed the properties file, the win32com.dll file in the right places.

Do you know what the problem may be?

thank