I came across the issue the other day when i was updating a server, basically I’ve opened up the Windows Update homepage to apply some updates and i was receiving a 403 forbidden error.
You may also see the Below error in the Event Log also.
Source : crypt32
Event Id : 8
The first thing to check when you get a problem with the windows update is the windows update log. Find the Window update log in the following location “%systemroot%windowsupdate.log”.
To find the most recent error received we need to got to the very bottom of the log (Ctrl + End). As you can see, the error just jumps out at you :)
FATAL: Update required for C:WINDOWSSysWow64wuweb.dll: target version = 7.2.6001.788, required version = 7.4.7600.226
So what we need to do is update the windows update agent to the required version. For the Version number “7.4.7600.226” the url is http://support.microsoft.com/kb/946928. If you have a different agent version require you should be able to find a download link with a quick Google search.