HOW TO CURE "This add-on is managed by your administrator" message while managing an add-on in Windows XP SP2

"This add-on is managed by your administrator" message while managing an add-on in Windows XP SP2

When you try to enable or disable a browser add-on via the Add-on Manager in Internet Explorer, Windows XP Service Pack 2, you may see this message in the Add-on Management dialog.

"This add-on is managed by your administrator"

This happens if the particular add-on is restricted via the Group Policy Editor or via the registry.

To clear all the add-on Policy settings,
start
run
type GPEDIT.MSC and navigate to this path:
Computer Configuration | Administrative Templates | Windows Components | Internet Explorer | Security Features | Add-on Management

In the right-pane, do the following:
Double-click Add-on List and set it to Not Configured
Double-click Deny all add-ons unless specifically allowed in the Add-on list and set it to Not Configured


Similarly, perform the above steps in this location: (Per-user setting)
User Configuration | Administrative Templates | Windows Components | Internet Explorer | Security Features | Add-on Management

(OR)

To accomplish the same via the Registry

Equivalent to Deny all add-ons unless specifically allowed in the Add-on list setting


Click Start, Run and type REGEDIT. Navigate to this key
HKLM \ SOFTWARE \ Microsoft \ Windows \ CurrentVersion \ policies \ EXT
-and-
HKCU \ SOFTWARE \ Microsoft \ Windows \ CurrentVersion \ policies \ EXT
In the right-pane, delete the value RestrictToList in both of the above locations
Equivalent to Add-on List Group Policy setting
Navigate to this key:
HKLM \ SOFTWARE \ Microsoft \ Windows \ CurrentVersion \ policies \ EXT \ CLSID
-and-
HKCU \ SOFTWARE \ Microsoft \ Windows \ CurrentVersion \ policies \ EXT \ CLSID
In the right-pane, delete the CLSID which corresponds to the Add-on which you want to manage.
By default, no entries exist there (in a clean installation)
Close Registry Editor and restart Windows.