The ConfigurePort API function lets you programmatically bring up the system dialog box for configuring a COM or LPT port. The function returns a non-zero value if successful (that is, the dialog appears). Here is the Declare of this function, and an example of its usage:
Private Declare Function ConfigurePort Lib "winspool.drv" Alias _ "ConfigurePortA" (ByVal pName As String, ByVal hWnd As Long, _ ByVal pPortName As String) As Long' display the dialog for serial port configurationIf ConfigurePort(vbNullString, 0&, "COM1:") = Then MsgBox "Unable to display the system dialog", vbCriticalEnd If' display the dialog for parallel port configurationIf ConfigurePort(vbNullString, 0&, "LPT1:") = Then MsgBox "Unable to display the system dialog", vbCriticalEnd IfRemember to always add a trailing colon when specifying the port name. Note that specifying a particular port (such as “COM2”) doesn’t make any difference, because the same dialog is displayed in all cases.
