If you're getting an w3wp.exe exception while updating
Why
Without this, the update will not progress, and looks like this:
The reason why this happens, is said to be because: The user that the DC is using to stop the digimonitor services, doesn't have the necessary rights to do so.
Fix
Go to the services program, and stop the two digimonitor services yourself.
Then simply rerun the [yoursite]/installer.DoInstall.aspx (Just press F5)