Certain areas of the Windows Registry cannot be accessed due to the Permissions assigned (or lack thereof) for those keys. There are legitimate cases where you need to access a registry key to modify or retrieve a setting, and receive Access is Denied or similar errors when doing so. Some of the errors you may encounter are:
Error Creating Key
<key name> cannot be opened. An error is preventing this key from being opened.
Details: Access is denied.
Cannot create key: You do not have the requisite permissions to create a new key under <key name>.
To get access to a registry key, you’ll need to change or take ownership and then assign full control (or the required) permissions for your user account. Here are the instructions to do the same in Windows.
(The screen shots are from a Windows 10 computer, but the steps are exactly the same in Windows 8 and 8.1. In Windows Vista & 7, there is a slight change in the permission dialog boxes, where ownership can be set by clicking the Owner tab in the Advanced Security dialog. Owner tab has been removed in Windows 8 and higher.)
Take Ownership of a Registry Key
1. In the Registry Editor (Regedit.exe) window, navigate to the branch for which you want to modify the permissions. Right-click on the key, and choose Properties.
2. Click the Advanced button.
3. In the Advanced Security Settings dialog, note down the owner. If it displays the message Unable to display current owner, or if your account isn’t the current owner, click Change
4. Type your user account name and click OK.
5. Your user account is showing up as the owner, but the change wouldn’t not applied until you click Apply.
If you also want to take ownership of the sub keys under the selected branch, click Replace owner on subcontainers and objects, and then click Apply. Don’t close the dialog yet.
(If using Windows Vista or 7, click the Permissions tab in the Advanced Security Settings dialog, and follow rest of the instructions. The dialog boxes would be different in Windows Vista & 7 after Step 7, but it’s not that difficult to follow.)
Assigning Full Control Permissions for your User Account
6. You’ve just change the ownership of the key, but that’s not enough. You’ll need to assign necessary Permissions (usually, Full Control) to the specific branch in order to write to it.
7. Click the Add button in the Advanced Security settings dialog.
8. Click Select a principal
9. Type in your user account name, and click OK.
10. Click Full Control checkbox to enable it.
You’re now added your user account Full Control permissions.
That’s it. Add as many entries as you need, such as for Administrators, SYSTEM etc. as required.
About the author
Ramesh Srinivasan founded Winhelponline.com back in 2005. He is passionate about Microsoft technologies and has a vast experience in the ITeS industry — delivering support for Microsoft's consumer products. He has been a Microsoft MVP [2003 to 2012] who contributes to various Windows support forums.