You require permission from TrustedInstaller to make changes to this folder

Question

You require permission from TrustedInstaller to make changes to this folder

Real Ouimet 40

I am trying to delete a Win 11 system folder:C:\Program Files (x86)>Common Files>System>msadc

I get the message:

"You require permission from TrustedInstaller to make changes to this folder"

I need to take Ownership of Files & Folders in question, but cannot get the right information on how to do it so as administrator, I can make changes to the folder in question.

Can someone please help me?

Moved from: Sysinternals

Locked Question. You can vote on whether it's helpful, but you can't add comments or replies or follow the question.

RLWA32 52,931 Reputation points

2025-12-14T12:54:15.44+00:00

@Real Ouimet, Its not clear to me what you want to achieve. For example, you wrote "I am trying to delete a Win 11 system folder..." and also "...so as administrator, I can make changes to the folder in question." To me, deletion and modification are not the same thing.

Windows uses restrictive security descriptors on system folders/files to prevent users, including Administrators, from taking actions that could damage the system.

Before taking any drastic action I suggest you fully describe the actual problem you are trying to solve by deleting/modifying a system folder.
Ishika Darra 0 Reputation points

2026-06-03T13:25:03.0666667+00:00

Hello,

I want to remove some old files that were left behind after Windows updates because I am running low on storage space. However, I keep getting a message that I need permission from TrustedInstaller. Could you please guide me on how to safely identify and remove unnecessary files without affecting Windows performance?

Thank you.
Les Ferch 10,361 Reputation points Volunteer Moderator

2026-06-09T11:45:16.8466667+00:00

You can use a program that will give you TrustedInstaller access such as PowerRun, AdvancedRun, or my Right-Click Tools. That's safer than trying to change ownership or permissions. However, as I don't know the specific files or folders you're trying to remove, I cannot tell you if it's safe to remove them.
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Answer accepted by question author

Francisco Montilla 30,715 Independent Advisor

Hello,

First make sure you truly do not need msadc for any legacy app. Then create a restore point if you want a safety net. Now do the change.

Open Start, type cmd, right click Command Prompt and choose Run as administrator.

Take ownership of the folder and its contents. This assigns ownership to the local Administrators group so you can proceed:

takeown /F "C:\Program Files (x86)\Common Files\System\msadc" /A /R /D Y

Grant yourself full control. Using your signed in account avoids localized group name issues:

icacls "C:\Program Files (x86)\Common Files\System\msadc" /grant "%USERDOMAIN%\%USERNAME%":F /T

Delete or modify the folder as needed. To remove it completely use:

rmdir /S /Q "C:\Program Files (x86)\Common Files\System\msadc"

If you only needed to edit files and will keep the folder, consider restoring the original owner so future servicing works as designed.

icacls "C:\Program Files (x86)\Common Files\System\msadc" /setowner "NT SERVICE\TrustedInstaller" /T

If you still see Access is denied, reboot to Safe Mode, repeat the same commands, then boot back to normal mode.

Real Ouimet 40 Reputation points

2025-12-24T07:43:02.5033333+00:00

Sorry for the delay but I could not take care of this challenge before. Thanks a million.

1 additional answer

RLWA32 52,931 Reputation points

2025-12-14T12:54:15.44+00:00

@Real Ouimet, Its not clear to me what you want to achieve. For example, you wrote "I am trying to delete a Win 11 system folder..." and also "...so as administrator, I can make changes to the folder in question." To me, deletion and modification are not the same thing.

Windows uses restrictive security descriptors on system folders/files to prevent users, including Administrators, from taking actions that could damage the system.

Before taking any drastic action I suggest you fully describe the actual problem you are trying to solve by deleting/modifying a system folder.
Ishika Darra 0 Reputation points

2026-06-03T13:25:03.0666667+00:00

Hello,

I want to remove some old files that were left behind after Windows updates because I am running low on storage space. However, I keep getting a message that I need permission from TrustedInstaller. Could you please guide me on how to safely identify and remove unnecessary files without affecting Windows performance?

Thank you.
Les Ferch 10,361 Reputation points Volunteer Moderator

2026-06-09T11:45:16.8466667+00:00

You can use a program that will give you TrustedInstaller access such as PowerRun, AdvancedRun, or my Right-Click Tools. That's safer than trying to change ownership or permissions. However, as I don't know the specific files or folders you're trying to remove, I cannot tell you if it's safe to remove them.
Deleted

This comment has been deleted due to a violation of our Code of Conduct. The comment was manually reported or identified through automated detection before action was taken. Please refer to our Code of Conduct for more information.
Real Ouimet 40 Reputation points

2025-12-24T07:43:02.5033333+00:00

Sorry for the delay but I could not take care of this challenge before. Thanks a million.

Answer 1

To take ownership of the folder and make changes, you can follow these steps:

Open Command Prompt as Administrator:
- Search for "cmd" in the Start menu, right-click on Command Prompt, and select "Run as administrator".
Take Ownership of the Folder:
- Use the following command to take ownership of the folder:
```
     takeown /F "C:\Program Files (x86)\Common Files\System\msadc" /A
```
- This command will grant ownership to the Administrators group.
Grant Full Control Permissions:
- After taking ownership, you can grant yourself full control permissions with the following command:
```
     icacls "C:\Program Files (x86)\Common Files\System\msadc" /grant administrators:F
```
- This command gives full access to the Administrators group.
Delete the Folder:
- Now you should be able to delete the folder using File Explorer or by using the command:
```
     rmdir /S /Q "C:\Program Files (x86)\Common Files\System\msadc"
```

If you encounter any issues with non-canonical ACLs, consider using the Subinacl utility to change ownership and permissions on the folder as described in the context.

References: