Problem

Identifying and Resolving IRQ Conflicts in Windows 95 and Windows 98

Possible Symptoms

• You get an error message saying you have an IRQ conflict.
• Hardware that previously worked behaves erratically, or fails to work, after you install new hardware.
• There is a yellow exclamation mark beside a device such as an Ethernet adapter in the Windows Device Manager.

Resolution

IRQs are a limited PC resource ensuring hardware devices get a share of the CPU. When two devices share the same IRQ number, each is effectively trying to push the other out of the way.

These instructions apply specifically to a NETGEAR PCI Adapter, but they also generally apply to resolving any IRQ conflict.

• Note that many NETGEAR adapters work only with Windows 98 SE, not Windows 98. See Windows Adapter Card Compatibility.

To Identify an IRQ Conflict

1. Right-click My Computer, and select Properties.
2. Click Device Manager.
3. Double-click Computer at the top of the list.
4. On the View Resources tab, select Interrupt Request (IRQ).
5. Find the NETGEAR adapter in the list. Look at the hardware entries above and below, and see whether they have the same IRQ number as the NETGEAR adapter. If either does, then there is an IRQ conflict.

• An "IRQ holder for PCI steering" is not a hardware device and may share an IRQ with the NETGEAR adapter.
• Other devices may be able to share an IRQ. It is only the NETGEAR adapter sharing an IRQ that is of concern, here.

After you determine that there is an IRQ conflict, there are two ways to solve the problem. Try the following method, first:

To Resolve an IRQ Conflict by Reassigning IRQ Numbers

This method lets Windows automatically configure your adapter, again. (It is not recommended to change IRQs manually, since this gives Windows less flexibility when installing other Plug-and-Play devices, later).

1. Right-click My Computer, and select Properties.
2. Click Device Manager.
3. Locate Network adapters, and click the plus sign next to it to expand the list.
4. Highlight the NETGEAR adapter entry, and click Remove.
5. Click Close.
6. Shut down the computer (powering it off).
7. Remove the adapter physically from the computer.
8. Restart the computer.
9. When the computer has restarted and the desktop shows, shut the computer down again (powering it off).
10. Reinsert the adapter into a different PCI slot.
11. Restart the computer.
12. Install the NETGEAR adapter drivers.

If the above method does not work, then there are no "free IRQs" on your computer, and you must remove a device that is taking an IRQ. A likely candidate is a device that is taking the IRQ the NETGEAR adapter tries to use. Another likely candidate is the network card the NETWORK adapter is due to replace.

If you have an IRQ conflict at this point, and are unsure how to proceed, you may want to contact your computer maker's technical support.

Doc ID: N100055.asp Dec. 2, 2003

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