Unable to update 2 important updates error Code 66 A and Code 80070645 RRS feed

  • Question

  • When trying to update I get error Code 66 A and Code 80070645

    1st update: Security Update for Microsoft .NET Framework 4 on Windows XP, Windows Server 2003, Windows Vista, Windows 7, Windows Server 2008, Windows Server 2008 R2 for x64-based Systems (KB2446708)

    2nd update: Security Update for Microsoft Office 2007 (KB951550)

    The updates begin to install and this happens every time. I have shutdown and unplugged my machine. Run C cleaner and malware. Lost.

    Not sure if this is related or not but I am unable to install Microsoft Security Essentials either. This computer is pretty new. Just dont get it.


    • Moved by Carey FrischMVP, Moderator Tuesday, May 3, 2011 6:48 AM Moved to more appropriate forum category (From:Windows Vista Setup)
    Monday, May 2, 2011 4:46 PM


  • Hi,

    I would like to confirm if you are able to install other updates. If all updates fail, I would suggest you to follow the methods provided below and check if it helps.

    Method 1:

    First check windows update history to find the error code for the failed updates. Right click on the failed update and click on view.
    Check for the updates that failed in Update history.
    a. Open Windows Update by clicking the Start button. In the search box, type Update, and then, in the list of results, click Windows Update.
    b. In the left pane, click View update history.
    c. To view more information about an update, double-click it.

    Method 2:
    I would suggest you to resetWindows Update components and check if it helps. To do so run theFixitform the link provided below.
    Method 3:
    If the issue still persists I would suggest you to run theSystem Update Readiness Tool. Follow the troubleshooting steps provided in KB article below and check if it helps.


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    Thursday, May 5, 2011 9:54 AM