When you visit the Windows Update site, you receive a message similar to the following, even if you are logged on with administrative privileges:
Administrators Only (-2146828218) To install items from Windows Update, you must be logged on as an administrator or a member of the Administrators group. If your computer is connected to a network, network policy settings may also prevent you from completing this procedure.
To workaround this problem:
01. Use the Registry Editor to navigate to:
02. On the Edit menu, press Permissions.
03. Press Add and type Everyone into the Enter the object names to select (examples) box and press the Check Names button.
04. Press OK.
05. Highlight Everyone in the Group or user names list.
06. Press the Allow box for Full Control under the Permissions for Everyone heading.
07. Select every entry in the Group or user names box and insure that there is no Deny box checked.
08. Press the Advanced button and check the Replace permission entries on all child objects .... box on the Permissions tab.
09. Press Apply, Yes, and OK.
10. Press OK and exit the Registry Editor.
NOTE: If you are behind a firewall or you use a proxy server, check these settings.