UAC prompt for Task Manager. MMC blocked. What happened?

  1. Posts : 57
    Windows 11

    UAC prompt for Task Manager. MMC blocked. What happened?

    I don't know if a recent Windows 10 update changed something, or if I have a virus, or what, but my Win 10 Pro 64bit computer is behaving differently today than a day or so ago.

    If I try to open the Task Manager I get a UAC prompt.

    If I try to open Computer Management, I get a "This app has been blocked for your protection" message for MMC.EXE.

    I just downloaded MalwareBytes software and Edge blocked the download because it may be harmful. I was able to select KEEP and install the software. I am currently scanning my system, but nothing found so far.

    This messages normally do not appear on my system.

    I have not installed any new software recently, except for Windows updates. My user is an administrator and the only user on the system.

    One other item I've noticed is that some apps can take many minutes before they open. An example is Notepad. I clicked the icon in the Start menu and nothing happened. I then clicked on Notepad++ and it opened right away. After a few minute Notepad showed up.

    This is a 64 bit Windows Pro installation, build 19042.685 of version 20H2 with experience pack 120.2212.551.0.

    Can someone tell me why this is happening and how I could fix it?

    - - - Updated - - -

    FYI... MalwareBytes scan just finished and found no issues. I am installing TrendMicro Housecall now to perform another scan.
      My Computer

  2. Posts : 4,825
    Windows 11 Pro 64 Bit 22H2

    It's possible that Computer Management is being blocked by SmartScreen. We suggest disabling it and see if it helps. Follow the steps below:

    1. Click the Start button.
    2. Type smartscreen in the search bar.
    3. Click Change SmartScreen settings.
    4. Click the drop-down arrow in the Security row.
    5. Click Change settings beneath the WindowsSmartScreen row.
    6. Click Don't do anything (turn off Windows SmartScreen).
    7. Click OK.
      My Computer

  3. Posts : 57
    Windows 11
    Thread Starter

    When I type "smartscreen", the closest item I get is "App & Browser Control". All the smartscreen setting there are "off".

    One thing that I just notice... In the "This app has been blocked..." pop-up that I see when I try to open computer management it shows the publisher for mmc.exe as "unknown". I would expect that to say "Microsoft". If I go to mmc.exe and open the properties, I do see Microsoft under the "Details" page.
      My Computer

  4. Posts : 5,347
    Windows 11 Pro 64-bit

    Open command prompt as a administrator and execute Sfc /scannow command.

    Execute the "Change_UAC_Settings.bat" batch script to change User Account Control (UAC) settings in Windows 10.

    Execute "ResetLGP.bat" batch script to reset Local Group Policy settings to system default settings.
    UAC prompt for Task Manager. MMC blocked. What happened? Attached Files
      My Computer

  5. Posts : 57
    Windows 11
    Thread Starter

    I ended up just wiping the computer and doing a fresh Windows installation. It was due anyhow. System is much snappier now!
      My Computer


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