To change the COM port for a modem
You must be logged on as an administrator or a member of the Administrators group in order to complete this procedure. If your computer is connected to a network, network policy settings might also prevent you from completing this procedure.
1. Open Phone and Modem Options in Control Panel.
2. On the Modems tab, click the modem you want to configure, and then click Properties.
3. On the Advanced tab, click Advanced Port Settings.
If this option is not displayed, the modem does not support changing the assigned COM port
4. In Com Port Number, click the port number you want to use.
Notes