IOS Errors

Updated: 01/24/2018 by Computer Hope

Bad file or statement in the config.sys or autoexec.bat

Error XThe steps below should resolve the error "While initializing device IOS: Error: An I/O subsystem driver failed to load" at boot.

Temporarily rename your autoexec.bat and config.sys by following the steps below:

  1. Boot the computer to MS-DOS.
  2. Once at the DOS prompt type:
    C: <press enter>
    cd\ <press enter>
    ren autoexec.bat autoexec.ch <press enter>
    ren config.sys config.ch <press enter>
  3. Once the above has been successfully completed reboot the computer.

Additional information about the autoexec.bat and config.sys can be found on our autoexec.bat and config.sys page.

Issue with SMARTDRV.EXE or RMM.PDR

The steps below can resolve any of the following errors: "Windows protection error", "IOS error", "While initializing device IOS: Windows protection error. You must restart your computer.", "While initializing IOS: Windows protection error. You need to restart your computer.", "Windows initializing device IOS: Windows protection error. IOS failed to initialize, please restart" or "Windows initializing device IOS: Windows protection error. You need to restart your computer" in Windows 95.

Temporarily rename the SMARTDRV.EXE and the RMM.PDR by following the steps below.

  1. Boot the computer to an MS-DOS prompt.
  2. Once at the DOS prompt type:
    C: <press enter>
    cd\windows <press enter>
    ren smartdrv.exe smartdrv.ch <press enter>
  3. Once smartdrv.exe has been temporarily renamed reboot the computer to determine if issue is still present.

If issue persists, rename the RMM.PDR by following the steps below

  1. Boot the computer to an MS-DOS prompt.
  2. Once at the DOS prompt type:
    C: <press enter>
    cd\windows\system\iosubsys <press enter>
    attrib rmm.pdr -r -s -h <press enter>
    ren rmm.pdr rmm.ch <press enter>
  3. Once rmm.pdr has been temporarily renamed, reboot the computer to determine if issue is still present.

Issue with Windows 95 and AMD K6/2 (350MHz or faster), or an Athlon (1.1GHz or faster)

The steps below and information should help to resolve "Device IOS failed to initialize. Windows Protection Error. You must reboot your computer."

This issue is attributed to a divide exception in Ios.vxd. It is a limitation of the software, and is not indicative of a problem with the processor itself, which is functioning properly. This issue has been resolved in Windows 98 and all later releases of the Microsoft operating systems.

Other Windows corruption

If after following the above recommendations you are unable to resolve the issue, it is likely that your Windows installation is corrupted. In this case, we strongly recommended that you format and reinstall Windows.

Additional information