Cannot install .NET update through Windows Update

Posted on 2011-05-12
Last Modified: 2012-05-11
I’m currently having a problem trying to install an update to my Windows 7 Professional 64-bit laptop.   This whole situation started when I kept getting errors when trying to install an update for my laptop.  The update is KB2446708.  This is a security update for Microsoft .net 4.0 framework.  The update kept ending with error code 66A in the Windows Update application.

At first I tried to repair Microsoft .NET Framework 4 Client Profile by going into the appwiz.cpl console and running repair.  This ended up failing with the following error:  “Installation failed with error code: (0x80070643)”.  I did some searching on this particular error and found that it is most likely caused by incorrect registry keys.  So, I checked my keys:


Both keys had the right value associated with them.  So that could not be the problem.  The next thing that I did was to uninstall Microsoft Silverlight.  Once that was uninstalled I tried to repair the program again.  But to no avail.  From there I decided to just uninstall Microsoft .NET Framework 4 Client Profile and reinstall it.  But during the uninstallation process it gets interrupted by a failure.  This would be the same failure as when I tried to repair the program.  Again the error is:  “Installation failed with error code: (0x80070643)”.  I know that this error is quite generic so I have also attached my log file from uninstalling.  I ran a program called collect.exe that supposedly collects all of the error information and compiles it into one neatly organized zip file, but experts-exchange would not let me load the zip file because one of the directories was called ".NET".  So I can upload you certain files or email the whole zip directory if you want.  Just let me know.  Can anyone help me with this?
Question by:palmerc12
    LVL 15

    Expert Comment

    Check that the Windows Installer service is set to manual but not disable via the following steps:
    1.Click Start, click Run, type services.msc in the Open text box, and then click OK.
    2.In the Services (Local) list, right-click Windows Installer, and then click Properties.
    3.If the Startup type drop-down list is set to a value of Disable, select the Manual option from the Startup type drop-down list, and then click OK.
    4.Click the File menu, and then click Exit.

    If it's already set right, try to repair Windows Installer:
    1.Run regedit (Start > Run > Regedit)
    2.Go to the location
    3.Right click on this key and select "Export" to save the backup .reg file for late use
    4.Open an elevated command prompt. To do this, click Start, click All Programs, click Accessories, right-click Command Prompt, and then click Run as administrator. If you are prompted for an administrator password or for a confirmation, type the password, or click Allow.
    5.Type the following command, and then press ENTER:
    sfc /scannow
     Do not reboot when complete
    6.Double click saved .reg file from working machine and import registry
     settings into Vista.
    LVL 30

    Expert Comment

    LVL 30

    Accepted Solution

    Download .net removal tool.

    Select 4 from list and then remove will take some time.. restart the computer and then do windows updates....and install all the updates.

    LVL 1

    Author Comment

    Thanks ded9!  I ran the tool and all of my updates were applied.  The only problem is that now when i click on a folder anywhere on my c: partition, the default action is "cmd" instead of "open".  So it tries to put the folder into the command line instead of opening it.  Then it gives me an error:

    "This file does not have a program associated with it for performing this action.  Please install a program or, if one is already installed, create an association in the Default Programs control panel."

    Do you have any idea why this setting would have been changed when i installed this update?  Also, In addition to this previous update I  also installed SP1- for Windows 7 Professional 64-bit.  Do you think that this could be the culprit?
    LVL 30

    Expert Comment

    This could be caused by a faulty program that might have corrupted your user profile...nothing to do with ms updates..would recommend creating a new user account...restart the computer and login under the new account...check how it works

    LVL 1

    Author Closing Comment

    I was able to fix the problem.  What I had to do is go into the registry and delete the "cmd" sub keys from within these two keys


    I made copies first so that if i had to reinstall them i could.  As soon as i removed the two cmd sub keys the folder opened perfectly.

    Thank you ded9.  I appreciated all of your help.
    LVL 30

    Expert Comment

    Great will help other ..Thanks.


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