This kind of error is usually due to the following:
- The user logon account belongs to the Guest(s) or Limited Account Groups
- The security descriptor does not allow authenticated users to run Windows Update
- and/or
- "The Impersonate a client after authentication policy is missing the Administrator and Service account from the list of Users and Groups."1
One method of resolving this issue is to simply remove the account that is causing difficulty.
Click "Start" "Run"
Type "control admintools" and click "Ok"
Expand the "Local Users and Groups"
Select Users
Open the account that is currently used for Windows Update
Click on the member of the tab
Select the user account you want to remove and click "Remove"
Another method is to set the security descriptor:
First stop the automatic update service:
Click "Start" "Run"
Type "cmd" and click "Ok"
Type:
sc sdset wuauserv D:(A;;CCLCSWRPWPDTLOCRRC;;;SY)
(A;;CCDCLCSWRPWPDTLOCRSDRCWDWO;;;BA)
(A;;CCLCSWLOCRRC;;;AU)(A;;CCLCSWRPWPDTLOCRRC;;;PU)
Now, press Enter
You should receive a success message
Type "exit" to leave the command prompt
Try the Windows Update again
The other method you could use is to verify that the local Administrator and Service account are added to the security policy:
Click
here to see the article posted by Marc Liron on this error.
Another plausible cause for this error is that the "Automatic Updates" service is not running as the correct user. To fix this go to "Start" "Run" and type in "services.msc" Go to "Automatic Updates" right-click and select "Properties." Click on the "Log On" tab and make sure that the "Local System Account" is selected. If changed you may need to restart the system.
More information may be found
here.
1 from http://www.updatexp....0x800a0046.html