Similar to system files and folders, some registry keys and values in system registry have been protected from accidental modification or deletion by end-user. Windows operating system restrict and lock some important registry keys by not granting write access right to standard user accounts, and even administrators. Instead, these protected registry keys are owned by System or TrustedInstaller, and has read-only permissions for end-user.

When a user doesn’t have permissions to modify, edit, create, add, change, delete or remove a registry key with Registry Editor (RegEdit.exe), one of the following error messages which denied permissions is displayed:

Error Creating Key

Cannot create key: You do not have the requisite permissions to create a new key under Registry Key.

Registry Access Error

Error Creating Value

Cannot create value: Error writing to the registry.

Error Renaming Key or Value

The Registry Editor cannot rename Registry Key or Value. Error while renaming key or value.

Error Editing Value

Cannot edit Registry Value. Error writing the value’s new contents.

Error Deleting Values

Unable to delete all specified values.

Error Deleting Key

Cannot delete Registry Key: Error while deleting key.

When a registry key is blocked from change, user also cannot run a .REG registry registration entries to merge the registry keys, values or value data to the system registry with the following permission denied error message:

Cannot import RegistrationEntries.reg. Not all data was successfully written to the registry. Some keys are open by the system or other process.

Cannot Import Registry Keys with .REG File

In order to take ownership and grant full control (read and write) permissions and rights on the protected system registry key to fix permissions denied issue, follow these steps:

  1. Run Registry Editor (RegEdit).
  2. Navigate to the registry key which user wants to modify its security settings.
  3. Right click on selected registry key, and select Permissions.

    Edit Registry Key Permissions

  4. Click on the Advanced button.

    Advanced Registry Security Settings

  5. In “Advanced Security Settings” dialog window, go to the Owner tab.
  6. Select and highlight the currently logged on user name or Administrators group (if user is a member of Administrators” in the Change owner to: box.
  7. Select the tick the check box for Replace owner on subcontainers and objects option, and click OK.

    Take Ownership of Registry Key

  8. Back in “Permissions” dialog window, click on Add… button.
  9. Enter the user’s login user name in the Enter the object names to select text box, and click on the Check Names button.

    Add User for Permissions Granting

    If there is error with the user ID entered, correct the error. If there is no error found, click the OK button.

  10. Back in “Permissions” dialog window, select and highlight the newly added user name in Group or user names: section, and tick the checkbox for Allow access right next to Full Control in the Permissions for <user name> section.

    Note: Read permission is automatically selected when Full Control is granted.

    Click on OK when done.

    Taking Full Control Registry Key

    Tip: If user is a member of Administrators group, it’s possible to grant to Full Control access rights directly to Administrators too, which will be extend to all users with administrator’s privileges.

User can now perform any “operation” such as add, create, edit, change, modify, delete, erase or remove on the registry keys been granted full control permissions.

Update: Become the owner and grant full access permissions to registry key in Windows 10