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Fatal error during installation causes .NET Framework 4 to fail error code 66A

Anonymous
2012-04-27T20:04:17+00:00

**added error code to title**

original title: I cannot remove or repair .NET Framework 4 because:  Fatal error during installation.  What should I do?

Windows Update can't install the latest update for .NET Framework 4; it's tried automatically many times and failed, and when I try to update it manually it hangs up and does nothing.

Troubleshooting led me to a problem with corrupted files on my machine, with the solution being to repair Microsoft .NET Framework 4 via "Programs and Features' (Windows 7 Professional edition, 64-bit).

When I try to repair or remove Microsoft .NET Framework 4, either process fails after only a moment.  The result is a message saying that the repair or removal did not succeed because:  Fatal error during installation.

I've rebooted and shut down all applications except Norton 360 and tried again, but I can't remove or repair the .NET Framework 4.

The log of the error reads thusly:

OS Version = 6.1.7601, Platform 2, Service Pack 1

 OS Description = Windows 7 - x64 Service Pack 1

 CommandLine = "C:\Windows\Microsoft.NET\Framework64\v4.0.30319\SetupCache\Client\Setup.exe" /repair /x86 /x64 /parameterfolder Client

 TimeZone = Central Daylight Time

 Initial LCID = 1033

Using Simultaneous Download and Install mechanism

Operation: Repairing

 Package Name = Microsoft .NET Framework 4 Client Profile Setup

 Package Version = 4.0.30319

 User Experience Data Collection Policy: Disabled

Operation updated to: Uninstalling

ServiceControl operation succeeded!

MSI (C:\Windows\Microsoft.NET\Framework64\v4.0.30319\SetupCache\Client\netfx_Core_x64.msi) Uninstall failed. Msi Log: Microsoft .NET Framework 4 Client Profile Setup_20120427_143222587-MSI_netfx_Core_x64.msi.txt

Final Result: Installation failed with error code: (0x80070643), "Fatal error during installation. " (Elapsed time: 0 00:00:09).

I can post a much longer version with all details if it's helpful.  Can anyone offer advice?

Thanks!

PS - Microsoft Fix It tool does not find any errors so it won't resolve the issue and allow me to repair the .NET Framework.

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Anonymous
2012-08-02T00:22:37+00:00

Reinstalling Windows 7 with the format disk option from the DVD solved the problem for me.  After that, the .NET framework updated successfully (once it had gotten updated back up to the point to try it).  I no longer have any failed Windows Update items.

The clean install was a nice refresher anyway, so all in all it wasn't the end of the world.  But if you're going to go that route, make sure you back up ALL of your data and can reinstall all programs from download or DVD, before you do the format.

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  1. Anonymous
    2012-04-28T09:36:49+00:00

    Hi Clive,

    I would suggest you to follow the steps and check if it helps.

    Method 1: Run System File Check (SFC) scans and checks if it helps.

    How to use the System File Checker tool to troubleshoot missing or corrupted system files on Windows Vista or on Windows 7

    **Note:**System File Checker gives an administrator the ability to scan all protected files to verify their versions. If System File Checker discovers that a protected file has been overwritten, it retrieves the correct version of the file from the cache folder (%Systemroot%\System32\Dllcache) or the Windows installation source files, and then replaces the incorrect file. System File Checker also checks and repopulates the cache folder. You must be logged on as an administrator or as a member of the Administrators group to run System File Checker. If the cache folder becomes damaged or unusable, you can use the sfc /scannow, the sfc /scanonce, or the sfc /scanboot commands to repair its contents.

    Method 2: Disable and enable .Net FrameWork and then check if it helps.

    Follow the steps below and then check if it helps.

    a) Go to Start.

    b) Type Turn Windows features on or off and open it.

    c) Uncheck .Net FrameWork and click OK.

    d) Restart your computer.

    e) Open Windows Features on or off.

    f) Enable .Net FrameWork and restart your computer.

    Turn Windows features on or off

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  2. Anonymous
    2012-08-18T22:45:53+00:00

    Nope. I didn't format the HD but I did delete the partition thinking that would be a quicker alternative.  Strangely though, some of the .Net updates installed - but not all - after doing a BIOS update and repair of the Windows Installer (for the nth time). My particular MSI mobo model had memory problems associated with it so the BIOS was updated to fix the known issues. I don't know if that fix allowed some of the .Net updates to occur or not but I will reformat my HD and do a fresh install of the OS if the problem persists.  I wasted too much time on this frickin' problem already. Thanks again for your help! 

    Update:

    Formatted the HD and that did not resolve the problem. Uhg!.

    Update (Aug 8, 2012):

    Frustrated, I downloaded Auslogic BoostSpeed v5.4 and ran every repair tool offered in that program. It found several corrupted .Net files and repaired them. None of the MS Fix It tools could repair the problem nor did they even indicate that there was indeed a problem with corrupt .Net framework files.  I don't know if the issue is with .Net or Windows Update as it took repeated attempts (3 or 4) before all of the .Net updates were successfully downloaded and installed even with the repaired .Net files but all of the critical updates are installed now. Whew!

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  3. Anonymous
    2012-04-30T01:35:29+00:00

    Hi Clive,

    I would suggest you to follow the **"Method 2: Repair the .NET Framework"**from the link mentioned below and check if it helps.

    Error codes “0x80070643” or “0x643” occur when you install the .NET Framework updates

    **Note: "**Method 2" from the above article is applicable for your issue.

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  4. Anonymous
    2012-04-29T15:09:38+00:00

    Thank you for your suggestions.  Unfortunately, the problem persists.  SFC did not find any corruption.  I disabled .Net Framework, rebooted, re-enabled .Net Framework, and rebooted again without any problems, but when I subsequently tried to repair .Net Framework, it was still unsuccesful due to "Fatal error during installation".  I noticed that the installation progress bars showed "all files verified successfully" before proceeding to the second stage, and that's when it aborted.

    Also, I'm not sure whether or not this makes sense, but in "Programs and Features" the only .Net Framework I'm seeing is "Microsoft .Net Framework 4 Client Profile" (which I can't repair).  But in "Turn Windows features on or off", I only see "Microsoft .Net Framework 3.5.1".

    Does that version disparity provide any clues to the source of my issue, perhaps, or is that normal?

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