long story short, one of our domain controllers is won't update.
when an update is attempted it says the service is not running (checked and restarted yes it is) and event viewer says its error 0x80072ee2 but this apparently means there is a connection issue but as far as I can work out there isn't.
this isn't a short term issue either seems to have been going on since at least feburary.
Note: Server updates fall to another (more senior) member of the team please do not ask me why they have been so neglected. He doesn't know what the issue is so I'm just trying to get to the bottom of this.
EDIT: I've put trusted sites on and seems to have sorted it. not sure why I don't believe it set up like this one any other server.