© National Instruments Corporation C-1 PCI Serial for Windows Me/9x
C

Troubleshooting and

Common Questions

This appendix describes how to troubleshoot problems and answers some
common questions.

Freeing an Interrupt Request Level

To free an interrupt request level for your serial port, you must disable the
device that is using the interrupt request level. To view the system-wide
allocation of interrupt request resources and remove a device, complete the
following steps:
1. Select Start»Settings»Control Panel and double-click on the
System icon.
2. Click on the Device Manager tab.
3. Double-click on the Computer icon and click on the View
Resourcestab.
4. Click on the Interrupt Request (IRQ) button. Scan through the list of
IRQ settings to determine which devices are using which interrupt
request levels.
5. When you locate a device that you are not currently using, click on the
Cancel button.
6. In the Device Manager tab, double-click on the icon for that device.
7. In the Device usage field, a checkmark appears to the left of the current
configuration, usually Original Configuration (Current). Click on
the checkbox to remove the checkmark.
8. Click on the Resources tab and make sure that Use automatic settings
is unchecked.
9. Repeat steps 7 through 9 for each unused device.
10. Click on the OK button to save your changes.
11. Restart Windows Me/9x to assign resources to your serial port. Then,
complete step 6 in the Verify the Installation section of Chapter 2,
Installation and Verification.