1) Open 'Control Panel' folder in 'My Computer' and if needed set to show all contents.

2) Find and open 'System' setup in 'Control Panel'.

3) Select 'Device Manager' tab and locate the 'Ports (COM and LPT)' entry. Select the COM port that your modem or external ISDN TA is attached to and highlight. Right mouse button and select properties.

4) Select 'Port Settings' tab and set 'Bits per second' to '115200' or if possible '230400'. Should you have problems online lower 230400 to 115200. Set 'Data bits' to '8', 'Parity' to 'None' , 'Stop bits' to '1' and select 'Hardware' for 'Flow Control'. Now highlight and click on 'Advanced'.

5) Make sure that 'Use FIFO buffers' is ticked and then set 'Receive Buffer' and 'Transmit Buffer' to High. If you experience problems when connecting or online select the 'Defaults' option. Click okay and exit out of DeviceManager.

6) Click 'OK' and exit out of Device Manager. Windows will now usually restart.