I have four partitions on my computer, say c,d,e and f.Out of these windows is installed on c drive.
And I have two users on my computer, one is admin and another is InternetUser.I have configured the Internet User in such a way that it has zero permissions on my system except that it can be used to surf the net(with some defined firewall rules) and save a few files on its desktop.Except this it can't do anything on my computer.

I use internet only from InternetUser.
But still windows is able to "automatically update" my system.How can it write(update) my system from InternetUser and that also remotely.I think windows has some backdoor preinstalled on the OS.How can I find more about it,so that I can "update" others computers remotely.

Also I think that if I use a kernel level debugger(like Softice or Windbg) and monitor the system while it is connected to internet,I could find out more about this "automatic update".Had anybody done it before?