Windows Setup Was Unable to Update Your System Files

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Article ID: 125480 - View products that this article applies to.
This article was previously published under Q125480
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One of the following symptoms may occur:
  • Windows stops responding (hangs) during Setup, when it attempts to load, or at the End User License Agreement screen.
  • The Windows 98 Setup Wizard may appear as a black square on the screen when the computer hangs.
  • You are asked whether you want to overwrite the boot sector. Choosing Yes may allow you to complete the Setup procedure, but Windows hangs when it attempts to load.
  • The images on the screen become distorted.
After you restart the computer, you receive the following message:
Windows Setup was unable to update your system files

This may be caused by virus detection that is built-in to your machine, or by virus detection software running on your system.

To disable built-in virus detection you will need to run the configuration program for the CMOS that came with your machine, or contact your machine manufacturer.

To disable virus-detection software that you have running on your system, you may need to remove the lines that start the program from your AUTOEXEC.BAT or CONFIG.SYS files.

After you have disabled the virus detection software, re-start your machine and re-run Windows Setup. Once you have successfully completed setup, it is okay to re-enable the virus detection software.

NOTE: The following error message may also be encountered:

Warning: disk boot sector is to be modified, press Y to accept, and any key to abort.


Some computers include a feature that prevents applications from writing to the boot sector. Such features are normally in the form of anti-virus protection set in your computer's CMOS settings. If anti-virus protection is enabled, Windows cannot complete its installation, or it does not load properly.


Disable the anti-virus feature in your computer's CMOS settings, and then reinstall Windows. Once you have successfully installed Windows, re-enable the anti-virus feature.

For information about accessing your computer's CMOS settings, please consult your owner's manual or your computer manufacturer.

NOTE: In order to disable Compaq's SafeStart Manager in the CMOS settings, you must upgrade the BIOS to at least version 2.26b.

More information

The following computers have been found to display this problem:
  • Acma Pentium 120 computer

    • Award Modular BIOS v4.50G, copyright 1994-1995, Award Software
    • 586 PCI Green BIOS 52xver.A
    • Award BIOS v4.50 3.03G, dated 12.02.93, 84-93 VT82C486A

  • NCR 3150 laptop computers with a Phoenix BIOS dated 1993

    These computers have a Boot Sector Protect setting. If this option is enabled, you may receive the following error message at startup:
    Non-system disk or disk error. Replace and strike any key when ready.
    If you disable this option in the computer's CMOS settings, Windows should start normally.


Article ID: 125480 - Last Review: October 26, 2013 - Revision: 2.0
Applies to
  • Microsoft Windows 95
kbnosurvey kbarchive kbdiskmemory kberrmsg kbprb kbsetup KB125480

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