Windows 10: Suddenly Cannot Write to Any External Drive ("Write permission is denied...")

Hi,

This issue could occur due to changes in the settings. We suggest you to take ownership of a folder/file/drive from Explorer. To do it, follow the instructions below:

1. Locate the file/folder/drive on which you want to take ownership in Windows Explorer.
2. Right click on file/folder/drive, and select Properties from Context Menu.
3. Click on Security tab.
4. Select the Advanced button.
5. Click on Owner tab in Advanced Security Settings for User windows.
6. Click on Edit button and select user from given Change Owner to list if user or group is not in given list.
7. Click on other users or groups. Enter name of user/group and click ok.
8. Now select User/group and click apply and ok. Check Replace owner on subcontainers and objects if you have files and folder within selected folder.
9. Click OK when Windows Security Prompt is displayed.

10.  Owner name must have changed.

11.  Click OK to exist from Properties windows.

If issue persists, try taking ownership of a file/folder/drive from command line below:

1. Type CMD in the Search bar, and right-click on Command Prompt.
2. Select Run as Administrator.
3. Type the following command: takeown /f <foldername> /r /d y
4. Hit Enter.
5. To assign the Administrators group a Full Control Permissions for the folder/file/drive, use the following command: icacls <foldername> /grant administrators:F /T
6. Once you take ownership, you can grant permissions on those files or folders.

Let us know how it goes.

Sorry for the confusion. We suggest you to perform a Clean Boot first on your PC, you can refer to this article for the instructions: How to perform a clean boot in Windows

Once done, follow these steps:

1. Right click on the file/folder/registry key with which you’re having the issue and select Properties.
2. Go to Security tab and click Advanced.
3. On Advanced Security Settings window, click Change beside Owner. Take ownership of the item, even if you’re already the owner.
4. After taking ownership, check Replace owner on subcontainers and objects below owner’s name.
5. Check as well Replace all child object permissions entries with inheritable permission entries from this object on the bottom part of the window.
6. Click Apply.
7. Select Yes on Windows Security pop up.
8. Another pop up for Windows Security will appear, hit Yes again, and then OK.
9. Try to check if you will still get the same issue.

Let us know how it goes.