Troubleshooting MS-DOS Compatibility Mode on Hard Disks

Question

Troubleshooting MS-DOS Compatibility Mode on Hard Disks

Answer

This question was answered on June 15, 1999. Much of the information contained herein may have changed since posting.

The information in this article applies to: Microsoft Windows 95 Microsoft Windows 98

SYMPTOMS: The Performance tab in System properties shows that one or more of the hard disks in your computer is using MS-DOS Compatibility mode. MS-DOS compatibility mode may be in use for either the file system or for virtual memory. You may receive the following message: Compatibility Mode Paging reduces overall system performance.

CAUSE: MS-DOS Compatibility mode may be in use for any of the following reasons:

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

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

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.

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.

Author

Posted by Ken of Data Doctors on June 15, 1999