Locked out of all Microsoft related updates, websites & services..

I am having a seriously annoying issue with Windows Vista that seems to be
related to events that occur after i reboot my system, after installing the
updates available.

I install Windows Vista (fresh installation) and afterwards go about
updating the OS. THe update process proceeds almost effortlessly. Before
rebooting i am able to access msn live messenger, www.microsoft.com and a
host of other Microsoft related sites and services as I am doing now on this
forum.

However....

After rebooting my system with the new updates in place I find that I am no
longer able to log onto msn messenger, hotmail, microsoft.com or any other
website or service that has some affiliation with microsoft. I am also unable
to access windows vista update at all. The update utility just keeps on
looking for updates and doesn't find anything. Websites load perpetually and
never come up.

I don't know whats happening but it seems to be related to the updates i
install. Can anyone help me?