Tuesday, November 17, 2009

Windows Management Framework Core is already installed on your system

I've been trying to install Windows Update KB968930 on my XP SP3 machine and kept on getting this error:

Windows Management Framework Core Setup Error
Setup cannot proceed. Windows Management Framework Core is already installed on your system.

This update, I believe, is Powershell 2.0 (final)

To install Powershell 2.0 you first have to uninstall Powershell 1.0

I finally solved it and got it installed by uninstalling some stuff that has to be removed before you uninstall Powershell 1.0. This is what I uninstalled and the order in which I did it:

  1. Update for Microsoft Windows (KB971513)
  2. Update for Windows Internet Explorer (KB975364)
  3. Microsoft Base Smart Card Cryptographic Service
  4. Windows Powershell 1.0 MUI Pack
  5. Wndows Powershell 1.0
  6. Windows Management Framework Core

UPDATE 12/22/2009: You may find that after you've installed Powershell 2 you see an exception from mscorelib.exe when you reboot your computer and this error repeats three times. If you look at the Event Viewer and under System you will see an error from Service Control Manager: The .NET Runtime Optimization Service v2.0.50727_X86 service terminated unexpectedly.

To solve this problem you need to run the following in the new version of Powershell that you've just installed:

Set-Alias ngen (Join-Path ([Runtime.InteropServices.RuntimeEnvironment]::GetRuntimeDirectory()) ngen.exe)
ngen update

There will be pages and page of informational text displayed including errors and warnings and this will take a fair amount of time to run. Be patient and don't panic.

Source: https://connect.microsoft.com/PowerShell/feedback/ViewFeedback.aspx?FeedbackID=494515



  1. I got another error: "Access Denied". I'm signed in as Administrator and the system says the program is loaded, yet the framework update doesn't show in programs as an XP, SP3, update.

  2. Have you click the check box that says something like "show updates"?

  3. In a similar case I had a kernel panic coincidentally occurred while installing this instead. This resulted in a partially install that both didn't show up under Add/Remove Programs or the Wwouldn't install nor reinstall. It also did not show up under the Windows Installer Clean Up utility.
    The following worked for me.
    1) Start regedit
    2) Find "968930" minus ""
    3) Eventually finds HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\KB968930\SP10\KB968930
    4) Copy the value data of "UninstallCommand"
    5) Paste into a cmd prompt
    6) Wait for "Windows Management Framework Core has been successfully removed. [Finish]
    7) (Windows de rigeur cliche) reboot
    8) Reinstall WMFC

  4. I've also found that Quest software's Powergui for Windows Powershell leaves some read-only subkeys in the root of HKCR.
    Set the acls on these keys to allow Full Control by your installation / administration account, and the install will complete perfectly.
    Powergui still works afterwards, too. Which is nice.
    I figured this out by using sysinternals' process monitor: technet.microsoft.com/.../bb896645.aspx as follows:
    1) Create procmon filter: Include only file /registry / network events from update.exe
    2) Set procmon to drop filtered events.
    3) Capture with procmon during installation of KB968930
    3) Refine procmon filter to include only results of "ACCESS DENIED".
    That should tell you unequivocally where you're having the problem.
    OS: Small Business Server 2003, patched up to date (as of now).
    All the best, Ben.

  5. Administrators group can't write to registry key
    HKLM\Software\Microsoft\Windows NT\CurrentVersion\Svchost
    All installed successfully after getting Full Control permissions for Administrators.

  6. Hi, thank you for useful advices.
    Also, in addition to described need to check permissions for keys