Intel Motherboards Using 82371SB PIIX3 Component

Updated: Tuesday, February 18, 1997

Description

The retail version of Microsoft Windows* 95 (version 4.00.950) may not recognize the Intel 82371SB PIIX3 IDE controller on Intel motherboards, causing the BIOS to disable the secondary IDE channel. This can result in IDE devices (such as CD-ROM drives) not being detected or disappearing after the system is rebooted.

This affects only the retail version of Windows 95. The OEM version has an updated MSHDC.INF file included in the OPK release and is not affected by this issue.

Root Cause

The 82371SB is not included in the list of IDE controllers in the MSHDC.INF file shipped with the retail version of Windows 95. During installation, Windows 95 sees the IDE functionality but can't identify the exact controller type. It enables the primary IDE channel of the 82371SB, but assumes that the secondary IDE channel belongs to a non-plug and play ISA IDE controller. Windows 95 then adds this information to the plug and play configuration area. When the system is rebooted, the motherboard BIOS interprets this information as indicating an ISA IDE expansion card has been installed, and disables the onboard secondary IDE channel -- rendering any devices on this channel inaccessible. The most common symptom is that the CD-ROM drive will not be recognized by Windows 95 after rebooting the system.

Affected Products

This issue affects all Intel motherboard products with the 82371SB component.

Workaround / Action

To determine how the system has been configured, look in the Windows 95 Device Manager (click Start, Settings, Control Panel, double click on the System icon, then click on the Device Manager tab). Double click on Hard Disk Controllers. If you see the following drivers listed, the system has NOT been configured correctly:

	Hard Disk Controllers
		-Primary IDE Controller (single FIFO)
		-Standard Dual PCI IDE Controller
		-Standard IDE/ESDI Hard Disk Controller

An Install Wizard has been developed that adds an entry for the 82371SB IDE controller into the MSHDC.INF file. This utility (in self-extracting zip file format) is available from the Intel FTP site at ftp://ftp.intel.com/pub/patch/ideinfup.exe, or from the Intel BBS (503-264-7999). Download this utility and follow the instructions to update the hard drive configuration file.

Please note that this utility has been tested only on motherboards manufactured by Intel and may not perform identically on other products.

*Other trademarks and brands are the property of their respective owners.