Windows 10: UAC rundll32.exe prompt & application taskbar icon context menu options not functioning

Windows 10 Home v1803 build 17134.137

Two issues started around the same time a week ago:

(1) Taskbar application icon context menu opens but options do not function. (Unpin/repin didn't fix)

(2) Getting rundll32 UAC prompts when accessing certain settings like 'change screen saver' and 'change system sounds'.

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Windows, drivers, and programs did not update prior to the issues occurring; updating since has had no effect. SFC and DISM found nothing (multiple runs), new local user account suffers from same two problems.

:)

 

UAC rundll32.exe prompt when opening the settings in the Control panel

I'm using Win 10 Home x64 with the newest updates. Recently every time I open the mouse, keyboard, sound and few more settings in a control panel I get an annoying UAC prompt that always includes rundll32.exe. I have to confirm every operation connected
with rundll32.exe. It happens on any Windows account (admin or normal user). For example it looks like this when I try to open the "Playback devices" from the taskbar (it contains this path: "C:\WINDOWS\system32\rundll32.exe" shell32.dll,Control_RunDLL mmsys.cpl,,playback):





My UAC level is set to default level and I haven't detected any viruses. There's something interesting about the rundll32.exe file in the system32 folder. It has that little UAC icon (so it opens with the UAC prompt) and every other Win 10 PC I have shows
the normal icon (there is no UAC prompt when I open it). Even after deleting the file and copying it directly from the another PC (retaining its permissions etc. with the xcopy command), it suddenly has this UAC icon. The same file in the backup WinSxS folder
can be opened without UAC but when it's copied to the system32 folder, it changes immediately. It looks like rundll32.exe file in system32 folder doesn't have the flag "run as admin without the need for UAC elevation prompt" anymore. How can I solve this problem?

 

rundll32.exe error in windows 10

Hi Aaron,

Rundll32.exe is an application that is used to launch functionality stored in shared .dll files, because
DLL (Dynamic Link Library) files can't be launched directly.

Here are methods that we can do to resolve Rundll32.exe errors in Windows 10:

Method 1 – Replace the corrupted file using Startup Repair:

• In the search box, type Recovery options. Double-click Recovery options.
• Go to Advanced startup, click Restart now.
• A blue window will pop-up, select Troubleshooting.
• Select Advanced options > Startup Settings >
  Restart.
• On the new list with settings that will appear, select Enable debugging.

Method 2 – Use the scannow command:

• In the search menu, type cmd.
• Right-click Command Prompt >Run as administrator.
• Type the command sfc/scannow and press Enter.

The sfc/scannow command will scan all protected system files, and replace corrupted files.

Method 3 – Replace the corrupted Rundll file:

• Download a copy of the Rundll32.exe file from the Internet.
• Replace the missing or corrupted Rundll file with the new one.
  • Go to windows\system32\rundll32.exe.
  • Paste the new rundll32.exe file.

NOTE: Downloading a copy of the Rundll32.exe
file from the Internet may cause system issues, virus and malware infection.


The entire risk arising out of the use of the downloaded file remains with you.

Update us with the outcome so we can provide further assistance.

 

[W10/1703] Clean Install, Rundll32 UAC Prompt


...and most items from the taskbar context menu (from programs) mainly File Explorer.

I'm also having the DISM issue like most 1703-ers.

Initially I updated to 1703 from 16xx and programs I was previously using began to fail so I rolled back, and was met with a corrupted user profile (blank User image on logon).

Finally the weekend so I decided to Clean Install Windows 10 using the Media Creation Install, and now I'm on the 3rd re-clean install and :

- File Explorer is only opening as 1 instance, cannot open another.
- Cannot open any pinned items from the Taskbar > R.Click File Explorer > choose one of the pinned items, or File Explorer, nothing opens.
- Discovered the DISM issue trying to fix the above. [fixed, did not fix the above, hence this thread creation]
- Any program that requires to be run through rundll32.exe, requires a UAC prompt, quiet annoying. (ex: volume control, playback devices, startup and others)

Thank you in advance.

Windows 10 Pro x64
Microsoft Windows [Version 10.0.15063]