PCI Device Status Shows Error Code 29

• Microsoft Windows 95
• Microsoft Windows 95 OEM Service Release 2

SYMPTOMS

When you are viewing a PCI device in Device Manager, it may report error code 29 for the device's status.

CAUSE

This behavior can occur for either of the following reasons:

• The PCI device is disabled in the computer's BIOS or at the hardware level.
• In Windows 95 OEM Service Release 2 (OSR2), IRQ steering is disabled.

RESOLUTION

If the device is disabled, consult the device's documentation or manufacturer for information about enabling the device and assigning an IRQ to it.

If you are using Windows 95 OSR2, use the following steps to enable IRQ steering:

1. In Control Panel, double-click System.

2. Click the Device Manager tab.

3. Double-click the System Devices branch to expand it.

4. Click PCI Bus, and then click Properties.

5. Click the IRQ Steering tab, and then click the IRQ Steering check box to select it.

6. Click OK.

MORE INFORMATION

Windows 95 requires that the IRQ for a disabled PCI device be included in the PCI configuration information in the BIOS. If the BIOS does not enable the device (and therefore does not assign an IRQ to it), Windows 95 shows error code 29 because it cannot enable the device without an IRQ and it cannot assign an IRQ to a PCI device.

IRQ steering is the ability to intercept requests issued for an IRQ and route them to the next available IRQ. IRQ steering is disabled by default in Windows 95 OEM Service Release 2. Although Windows 95 supports most PCI chip sets, Windows 95 does not support IRQ steering prior to the release of OEM Service Release 2. IRQ steering is most useful on portable computers with docking stations on which the hardware state of the system frequently changes.