Windows Protection Error, device IOS

First and foremost, I have an immense respect for the people who answer these questions. I know it takes a lot of time and often headache to tackle this configuration problems; usually I'm the one doing such for family and friends. Now I'm the one that's been confounded for months.

In despair, I did an Internet search on "initializing device IOS" and found the recent question posted here at EE. I printed out the entire thread and tried everything there, even if I've already tried it before. I'll try to be as complete and descriptive to aid your efforts.

Problem: About 2 out of 3 system boots, I'll get an error message before Win95 completes startup. It'll be on a DOS-like screen, written at the top.

      "While initializing device IOS:
      Windows protection error. You must restart your computer."


      "Windows protection error. You must restart your computer."

After reboot, the system prompts me with the startup method menu (normal, safe mode, etc.). If I choose Safe Mode, nothing really happens. If I choose normal, whether or not I chose Safe Mode just prior, I may or may not get the error message. In order to get 'normal' system operation, I just continue hitting the reset button and choosing 'Normal' until I get into Win95. Then, when it finally will give me a full, normal boot, it will take an unusually long time with HD activity all the while.

Things I've tried to do:
-rename/delete "rmm.pdr". It appeared to regenerate.
-download and run "iosfix.exe".
-remove "autoexec.bat" and "config.sys".
-enter lame files for "autoexec.bat" and "config.sys" per <magigraf>'s prescription.
-renamed "smrtdrv.exe"
-removed all system devices and allowed a redetect by Windows

Other items of note:
-this all started after a board/CPU upgrade
-system devices were (will be?) double and sometimes up to quadruple entered in the my list of devices as seen at My Computer-Properties. This seems indiscriminate in it's choice of devices. Everything from display adapters to the system clock has fell to this phenomenon.
-after the error, windows will forget my preferences for the taskbar and file viewing (like, in list form with a toolbar and view in one reused window).
-after a recent video card replacement, I've been unable to remove the previous video's entry in the "Add/Remove Programs" list. It says I need to do this while in safe mode, but still will not let me remove it. This item does not appear in my list of system devices.
-I have two items in "Other Devices" with no driver installed. A "PCI Universal Bus" and a "PCI Bridge". I have no idea where to begin there...

Info for you:
-running Windows 95 4.00.950 B
-AMD-K6/2 350MHz, 64 MB RAM
-CD-ROM is unavailable in DOS mode, and is slaved to the HD. This may be unrelated, but I didn't want to leave anything unusual out.

Other than multiple recent crashes running my new "Starcraft" game <g>, nothing else seems out of the ordinary. This is my first post to EE and I've looked on with respect to the answers to many other questions. I hope that the resident experts continue that trend with this problem. Sorry if it's a rehash. :)

Who is Participating?
istal112898Connect With a Mentor Commented:
Glad I helped :).
I have found that this error is virtually always caused by one of two things:

1) Hardware failure (1 out of 10 times this is it).

2) Corrupted Win95 registry (9 out of 10 times)

For a solution, see:

Redbrawn please let me post this comment as an answer.
the answer is not correct. AMD-2-k6 350 has problem with Windows 95, Microsoft has provided a patch for it.
here it is:

Sorry Jhance but your answer is not correct.

                           Read Me First
                           Microsoft® Windows® 95 Update for AMD-K6®-2/350 and Above Patch for Windows 95
                           OEM SR2 and above fixes a software timing loop that is sensitive to processor frequency
                           and is not a processor erratum. Please note that this patch will not resolve issues
                           associated with any other versions of Windows 95 other than the OEM SR2 version. If you
                           have any other version other than OEM SR2, please contact technical support for further
                           options available to you.
                           To determine the version that you have on your system, please read below. If you are not
                           sure which version of Windows 95 you have, you can find out simply by checking your
                           System Properties. To do this, right mouse click on "My Computer" and select "Properties".
                           An OEM SR2 system will show a designator, such as "4.00.9500 B" as the version. The
                           number may vary slightly, but the letter designator will be a "B" for the OSR2 version.
                           Version designators without a "B", such as an "A" or nothing after the number, cannot
                           utilize this patch. For these versions, please contact technical support for further
                           assistance to resolve this issue.
                           If you are starting Windows 95 OSR2, OSR2.1, or OSR2.5 on a computer with an AMD-K6-2
                           processor running at speeds of 350 MHz and above, you may receive one of the following
                           error messages:

                                Device IOS failed to initialize.
                                Windows Protection Error.
                                You must reboot your computer.

                           The first error is a result of a divide exception in IOS.VXD, the second is due to a similar
                           error within ESDI_506.PDR or SCSIPORT.PDR. This problem is very intermittent at 350MHz.
                           Note that it is necessary to reboot the computer after the error occurs. If the error does
                           not occur, the system will run normally.
                           NOTE: This download is not intended for use on computers running Microsoft®
                           Windows® 98. This issue has been addressed in Microsoft® Windows® 98.
                           System Requirements

                                Microsoft Windows 95 OSR 2.X

                           How to Download
                           1. Create a folder by right-clicking on the desktop, click New, and then click Folder. Type a
                           name for the folder and press enter.
                           2. Click the Next link to go to the list of download sites. Choose a download site and click
                           AMDK6UPD.EXE to begin downloading. In the File download dialog box that appears on
                           your screen, click Save Program to Disk.
                           3. Choose to save the file in the folder you just created, then click Save.
                           4. Open that folder and double-click amdk6upd.exe to install the program files. Be sure to
                           read the &ldquo;Read-Me&rdquo; files for additional information.
                           How to Use
                           You don't need to do anything after installing.
                           How to Uninstall
                           Using Windows Explorer, locate the file AMDK6_UN.INF in the Windows\INF\QFE folder,
                           right-click on the file AMDK6_UN.INF, and choose Install. You will be prompted for the
                           Windows 95 installation CD or diskettes. Choose the appropriate path. You may be
                           prompted to replace the newer file with an older version of the file. To uninstall this
                           update, choose to Replace the newer file. Restart the computer for the changes to take

                           Windows 95 Update for AMD-K6®-2/350
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I'll stand by my answer for the moment.  I'm aware of the AMD K6/350 issue but it's very rare.  It only happens on a very small percentage of systems.
Jhance sorry to disagree but this problems arise only due to that time loop. the system gives this problems all the times. This is not a Registry problem.
My comment as an anwer is closer to the problem. I have had those problems before and it happens almost always. If it were rare it would not exist a fix.

Please read in WWW.AMD.COM about it.
redbrawnAuthor Commented:
Hello again to all. I understand that speedy replies and testing of hypotheses are important and encouraged here, so I apologize for the delay.

I tried the answer proposed by -jhance- as soon as I was notified of it. It was a very lengthy process that didn't repair itself through the very end. My last action was to format my hard drive and do a clean install of Windows. Imagine my dismay when even that didn't solve my problem.

I called the manufacturer of the motherboard and they told me of the AMD 350 and up errors that occur when running under Win95 OSR2, which was what I said I had in my question. After barely being able to get online again, I went straight to the AMD website and found the answer to my question easily. It's a very small download that take all of 5 seconds to fix. It was rather anti-climactic to say the least. They should try to publicize that page in the search engines - it doesn't show up very readily. <g>

I thank you for your replies. Unfortunately I must reject the first answer, and -istal- should get credit for the correct answer. Now if only that could bring back my hard drive... :)
redbrawnAuthor Commented:
A good explanation of the problem was given at AMD's site for anyone who may be able to help future users. Here's the URL:
redbrawnAuthor Commented:
your welcome :)
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