MS-DOS Compatibility Mode Problems

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.

MS-DOS Compatibility Mode Problems with PCI-IDE Controllers
http://support.microsoft.com/default?kbid=151911

A Gold Mine For MS-DOS Compatibility Mode Problems.
http://support.microsoft.com/support/windows/faq/hwmm/a>

Windows 95 Frequently Asked Questions About Multimedia
Windows 95 Hardware and Multimedia Questions
Click a question to display the answer.

Hardware
When I start my computer, I receive an error message that states "Missing Operating System." What's wrong?
http://support.microsoft.com/default?kbid=80304

When I start my computer or run programs I receive a message stating "Data Error Reading Drive C." What is happening?
http://support.microsoft.com/default?kbid=150532

When I start my computer I receive a "Parity Error" message. Is this a Windows 95 error?
http://support.microsoft.com/default?kbid=134503

When I start my computer, random errors occur or the display is garbled. This does not happen if I start my computer in Safe mode or use the standard VGA driver. How can I use the best color and resolution my display is capable of?
http://support.microsoft.com/default?kbid=127139

When I started Windows 95, I received a message stating that the Master Boot Record on my computer had been modified. What should I do?
http://support.microsoft.com/default?kbid=143281

My computer seems to be operating slowly and the Performance tab in System properties indicates that one or more hard disks is using MS-DOS Compatibility mode. How can I use 32-bit disk access with my hard disk(s)?
http://support.microsoft.com/default?kbid=130179

I recently installed a new modem. Why does my mouse stop functioning when I attempt to use the modem?
http://support.microsoft.com/default?kbid=82545

What is the best way to install an internal modem in a computer running Windows 95? What are some of the problems I might run into when I am installing an internal modem?

http://support.microsoft.com/default?kbid=152064

Multimedia

Why does the Performance tab in System properties show that my CD-ROM drive is using MS-DOS Compatibility mode? [THE LIST]
http://support.microsoft.com/default?kbid=151634

Does Windows 95 include a protected-mode driver for my CD-ROM drive? If not, how do I obtain one or configure my computer if one is not available?
http://support.microsoft.com/default?kbid=151634

If I am loading protected-mode drivers for my CD-ROM drive, do I still need to load the real-mode CD-ROM drivers?
http://support.microsoft.com/default?kbid=151634

If I am using real-mode drivers for my PCMCIA CD-ROM drive, can I still use protected-mode drivers for the PCMCIA card socket and the other PCMCIA card devices that I use?
http://support.microsoft.com/default?kbid=136553

Why can't I access my CD-ROM drive when I boot to a command prompt or MS-DOS mode, or from a floppy disk?
http://support.microsoft.com/default?kbid=135174

MS-DOS Compatibility Mode When Booting from Removable Disk
http://support.microsoft.com/default?kbid=163317

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FIXING MSDOS Compatibility Mode Problems

Always back up your registry 1st.
HKEY_LOCAL_MACHINE\SYSTEM\CURRENT CONTROLSET\SERVICE\VXD\IOS
There make you "String Value Key" NOIDE=00 or NOIDE=01
You'll have to experiment with the value

To cause Windows 95 to attempt to reinitialize the protected-mode IDE driver, remove the NOIDE entry from the following registry key:

HKEY_LOCAL_MACHINE\SYSTEM\CURRENT CONTROLSET\SERVICES\VXD\IOS

After you update the registry, restart Windows 95. Windows 95 will then attempt to initialize the protected-mode driver for the controller. If no problems are encountered, the file system and virtual memory will operate in 32-bit mode, and Device Manager will not display an exclamation point in a yellow circle for the IDE channels.

If the protected-mode driver is not initialized properly, an error message will be displayed and the NOIDE registry entry will be re-created. Windows 95 will use the MS-DOS compatibility mode file system the next time you start the computer.

2nd:
Search your registry for "BAD_IDE" [no qoutes]
EXAMPLE:
[HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Class\hdc\0000]
"InfSection"="BAD_IDE"