Windows Serial Port Troubleshooting

1. Press the 'CTRL,' 'Shift' and 'ESC' keys at the same time to make the 'Task Manager' window appear. Select the 'Applications' tab and then right-click each application listed that uses serial ports and click 'End Task' in the menu that appears. Open the program you are using to access the serial port and try connecting through the serial port. If serial port communication is still not working proceed to the next step.
2. Select the 'Start' button, then right-click 'Computer' and select 'Manage' in the menu that appears. Select 'Device Manager' in the left pane of the window that appears. Click the '+' next to the 'Ports' header in the right pane to expand the 'Ports' section. Double-click on the serial port that is not operating properly and the serial port 'Properties' window will appear.
3. Select the 'Port Settings' tab and confirm that the settings displayed match the settings for the serial device to which the Windows computer is connected. If the settings do not match, then click the drop down box for each setting that does not match and click the correct setting. Click the 'OK' button. Open the program you are using to access the serial port and try connecting through the serial port. If serial port communication is still not working proceed to the next step.
4. Select the 'Resources' tab and click the 'Set Configuration Manually' button. Click to clear the 'Use automatic settings' check box. Click the 'Setting based on' drop down box and click on the setting at the top of the menu. If the 'Conflicting device list' window displays conflicting devices, click the drop down box and select the next setting. Repeat this step until the 'Conflicting device list' window displays 'No conflicts.' Click the 'OK' button and the serial port is now ready for use.