First of all thanks both for the Welcome message and the Reply.
About my problem I read both sites and I didn't get anything stable to be used.
Actually my program does a directly I/O on COM port and we didn't connected the printer (Zebra printer) on Client so I don't know if this printer is recognized by Windows (:S... sorry about that but I don't have this printer here).
There are a way to make a I/O using a windows printer ? If I got this printer recognized on windows.