Unexpected Behavior When Updat_cd.com File Is Loaded at Startup

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Article ID: 186670 - View products that this article applies to.
This article was previously published under Q186670
If this article does not describe the error message that you are receiving, view the following Microsoft Knowledge Base article to view more articles that describe error messages:
315854 Windows 98 and Windows Me Error Message Resource Center
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You may experience any of the following symptoms:
  • You receive fatal exception error messages while Windows 95/98 Setup is copying files to your computer.
  • You receive the following error message when you run Updat_cd.com from a Winstart.bat file:
    Explorer.exe caused an invalid page fault in module kernel32.dll
  • One or more drives use MS-DOS Compatibility mode.
  • You are unable to run ScanDisk for Windows.
  • Your CD-ROM drive cannot be found after Windows 95/98 Setup is completed.
  • Some programs, such as Corel Graphics, Microsoft Word, and other Microsoft Office programs do not run properly, and you experience unexpected behavior when running these programs.


These issues can occur if you are running a program that installs the Updat_cd.com file. The Updat_cd.com file is incompatible with Windows 95 and Windows 98.


To resolve these issues, prevent the Updat_cd.com file from loading when you start Windows. To do so, follow these steps:
  1. Restart your computer to a command prompt. For Windows 95, press F8 when you see the "Starting Windows 95" message, and then choose Command Prompt Only from the Startup menu.

    For Windows 98, restart your computer, press and hold down the CTRL key after your computer completes the Power On Self Test (POST), and then choose Command Prompt Only from the Startup menu. For more information about Windows 98 startup, see the following article in the Microsoft Knowledge Base:
    ARTICLE-ID: 178548
    TITLE : No "Starting Windows 98" Message at Startup
  2. At the command prompt, type the following commands, pressing ENTER after each command:

    cd windows
    edit winstart.bat
  3. Disable the following line in the Winstart.bat file by typing "rem" (without quotation marks), and then pressing SPACEBAR at the beginning of the line:

    c:\windows\updat_cd.com c:\cd.sav
  4. Press ALT+F, press S (to save), press ALT+F, and then press X (to exit).
  5. Restart your computer normally.


The Updat_cd.com file incorrectly hooks interrupt 21 in Windows 95/98. This can prevent Windows 95/98 operations that require direct disk access from functioning properly.

The Updat_cd.com file is installed by earlier Corel programs and by the following programs distributed by MicroStar:
  • 200 Great Games for Windows
  • 300 Great Games for Windows
  • Casino Games Gold Edition
  • Unearthed Arsenal (a Diablo add-on package)
The third-party products discussed in this article are manufactured by vendors independent of Microsoft; we make no warranty, implied or otherwise, regarding these products' performance or reliability.


Article ID: 186670 - Last Review: January 23, 2007 - Revision: 1.2
  • Microsoft Windows 95
  • Microsoft Windows 98 Standard Edition
  • Microsoft Windows 98 Second Edition
kbdiskmemory kbenv kberrmsg kbfaq kbfatalexerr0d kbfatalexerr0e kbhardware kbinvalidpagefault kbkern32dll kbprb kbsetup KB186670

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