PCI IDE Controller Compatibility Mode Error

PCI IDE Bus Compatibility Mode Errors

After installing Windows 95 on your system, you may have one particular error that seems to be troublesome to resolve, and that is with the PCI IDE bus controller on the motherboard. This “PCI IDE” bus is for your IDE hard drives and any CD-ROM drives you attach to the motherboard. The typical error looks like this.


“Your Multi-function device “Standard Dual PCI IDE Controller” has some child devices using 32-bit drivers and others using compatibility mode drivers. Their Configuration is not supported, so your computer has been halted to prevent corruption.

After you restart your computer, Windows will use compatibility-mode drivers for each child device attached to this multi-function device. If you want to use 32-bit drivers, you may be able to obtain an updated driver for the device that caused the problem by contacting your hardware manufacturer or you can disable the device.

Press any Key to Continue”


Since Windows 95 was developed and released prior to the release of most of the more popular chipset, such as Intel’s TX, FX, LX, BX as well as the VIA chipset series, this error is quite common. It can be easily resolved though if you take your time and accurately determine what is causing the error that is occurring.

NOTE: Floppy disk drives and CD-ROM drives operating in MS-DOS Compatibility mode cause the Performance tab to display the message “Some drives are using MS-DOS compatibility” for the file system, but this article applies only to troubleshooting hard disks operating in MS-DOS Compatibility mode.

For information about troubleshooting floppy disk drives, please click the article number below to view article# Q131690 in the Microsoft Knowledge Base: entitled: Troubleshooting Floppy Disk Drive Problems in Windows

Here are the typical reasons for this error and hopefully how to fix it. Use the Performance tab in System properties to identify which drive is using MS-DOS Compatibility mode and why.

  • An “unsafe” device driver, memory-resident program, or virus hooked the INT21h or INT13h chain before Windows 95 loaded.

    The first place to look would be your Autoexec.bat and your Config.sys files and make certain that your CD-ROM device drivers are not being called. If necessary, rename them to Autoexec.old and Config.old and then restart the computer.

    The second would be to make sure that your system is virus free!

    If the driver name listed as causing MS-DOS Compatibility mode is MBRINT13.SYS, your computer may be infected with a boot-sector virus, or you are running real-mode geometry translation software (for an IDE hard disk with more than 1024 cylinders) that is not compatible with Windows 95protected-mode disk drivers.

    You may also want to review Article # Q126855 entitled: Windows 95 Support for Large IDE Hard Disks in the Microsoft Knowledge Base to make sure that the size of your hard drive is compatible with Windows 95.

    You may also want to review these articles as well:  Article #Q82923 entitled: Methods to Detect a Boot-Sector Virus and Article# Q129972 entitled: Description of Computer Viruses.

    Another area to check would be if you have a driver for some other device in your Autoexec.bat or Config.sys that may not be Windows 95 compatible. If a driver that is listed in the CONFIG.SYS file is named, contact the driver’s manufacturer to determine whether there is a version of the driver that allows protected-mode access in Windows 95.

  • The hard disk controller in your computer was not detected by Windows 95.

    This is the most common of all of the reasons for this error, as Windows 95 has no idea how to identify and install your PCI IDE motherboard chipset, but it can detect its presence.

    In order to resolve this, your motherboard and/or computer should have come with a Floppy or CD-ROM disk with the drivers on it. In addition, both Intel and VIA make their drivers available for download.

    The procedure: (1) Locate the drivers that you need; (2) Open Device Manager and remove the PCI IDE Bus controller entries by clicking on them to highlight and then click the remove button; (3) Install the drivers from the diskette or CD-ROM. Follow the instructions that came with the disk; (4) Now restart your computer. Windows 95 should now find the drivers and install the PCI IDE bus correctly.

    Note: If you are one of our customers, and your system came installed with Windows 95 originally, then please check your diskette pack for your PCI IDE Busmaster Drivers disk.

  • The hard disk controller was removed from the current configuration in Device Manager.

    There is a resource conflict between the hard disk controller and another hardware device.

    This is usually caused by Windows being unable to recognize the PCI IDE bus. Loading the driver should resolve it. It may be a bit troublesome to sort out, but the PCI IDE bus should be the first error cleared if present in Device Manager.

  • The Windows 95 protected-mode driver is missing or damaged.

  • The Windows 95 32-bit protected-mode disk drivers detected an unsupportable configuration or incompatible hardware.

    For these last two errors, repeat the process of reloading the PCI IDE busmaster drivers.

As a last resort, presuming that you have done all of the above and the error is still present, you can try and force Windows 95 to recognize the PCI IDE bus by editing the registry.

Note: Editing or changing the Windows registry without at least some experience in doing so could render your computer inoperable in that you may not be able to start Windows 95! Proceed at you own risk!

To make this registry change, please follow this procedure:

  1. Click Start, Run and type in “regedit” (without quotes) and touch the enter key.

  2. The registry editor will open and look like this:
  1. Now drill down to the “IOS” section as noted in the picture by clicking on the respective plus “+” signs to expand that area.

  2. Take note of the data value entries to the right of “NoIDE” and “Start”, they are indicated as “1”. These will need to be changed to read as “00” (without the quotes).

  3. Right click on the NoIDE name and then choose “Modify”. Now change the entry from “01” to “00” (without quotes). When you are done, it will look like this:

  1. Now close the registry editor and restart your computer. Check the Device Manager to make sure the problem has been resolved.

Would you rather go back to the beginning?   Then click  


About Dewwa Socc

Sahifa Theme License is not validated, Go to the theme options page to validate the license, You need a single license for each domain name.