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Microsoft KB Archive/157924

From BetaArchive Wiki

Err Msg: "IOS Failed to Initialize" on Boot


The information in this article applies to:

  • Microsoft Windows 95
  • Microsoft Windows 95 OEM Service Release, versions 1, 2, 2.1


When you restart Windows 95 after installing a program or making a configuration change to your computer, you may receive one of the following error messages:

Windows initializing device IOS: Windows protection error. IOS failed to Initialize, Please restart

While initializing IOS: Windows protection error. You need to restart your computer.

Windows initializing device IOS: Windows protection error. You need to restart your computer.

After the error message is displayed, you may not be able to start Windows 95 normally. However, you should be able to start Windows 95 in Safe mode.


It may also be possible to start Windows 95 normally after using the following procedure:

Boot Windows 95 in Safe mode or to a command prompt.

Perform one of the following two steps:

  • Edit the Config.sys and Autoexec.bat files and disable any references to Smartdrv.exe. To disable a line, type rem at the beginning of the line.
  • Rename Smartdrv.exe to another name.

Restart your computer normally.

For additional information about IOS error messages, click the article numbers below to view the articles in the Microsoft Knowledge Base:

Q225497 Windows 95 May Fail to Boot Due to I/O Subsystem Failure

Q164666 Err Msg: While Initializing Device IOS...

Q192841 Difficulties Using AMD K6-2 or Athlon Central Processing Unit

Q168866 FIX: IOS Failed to Initialize Error During Installation


Microsoft has confirmed this to be a problem in Microsoft Windows 95 and OEM Service Releases. An update to address this problem is now available, but should be applied only to systems experiencing this specific problem. Unless you are severely impacted by this specific problem, Microsoft does not recommend implementing this update at this time. Contact Microsoft Technical Support for additional information about the availability of this update.


The problem occurs only on certain system configurations, and does not occur if Internet Explorer 4.0 is installed on your computer. These system configurations have a minimum of 32 MB of RAM and a large number of device drivers. The problem is rare and can occur only at startup. Users whose systems are starting successfully today are not impacted.

Additional query words: msn msnetwork w95susd

Keywords : kbenv kberrmsg osr2 win95
Issue type : kbprb
Technology : kbWin95search kbOPKSearch kbWin95 kbWin95OPKOSR2 kbWin95OPKOSR1 kbWin95OPKOSR210

Last Reviewed: March 4, 2001
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