How to Resolve IRQ Conflicts in Serial or Parallel Ports

If you've installed a new serial or parallel card and it's not working, the new port may be trying to use an IRQ setting assigned to an old port. You can disable the existing ports via the Control Panel.

Difficulty: Moderately Easy

Instructions

Things You'll Need:

• Serial/parallel Cards

1. Click Start, point to Settings, and then click Control Panel.

2. Double-click System, and then click the Device Manager tab to display all devices.

3. Click the (+) sign next to Ports (COM and LPT) to display current ports. An exclamation point (!) in a yellow circle will appear next to the names of ports that are conflicting with the new ports.

4. Double-click the names of the conflicting COM or LPT ports.

5. Click the check box by "Disable in this hardware profile."

6. Move any devices from the conflicting ports to the new ports.

7. Click OK, and then restart the computer. Windows should now detect the new serial or parallel ports and the attached devices.

on 11/22/2005 It's much easier, while in System Properties, to simply remove ALL the ports, then reboot and allow Windows to reinstall them. Windows itself should assign non-conflicting resources for the ports. If that fails, you can disable some.