Just been reading this thread after suffering a 30 minute overall routine minor auto update on my vista laptop. (1.8GHz core2duo 3MB RAM). Reboot took 20 minutes! I have suffered this issue almost from square 1. Repeated reboots, defrags and occasional use of CCleaner have helped a little in the past but its getting beyond help now, it seems.
It beggars belief that over 4 YEARS from the OP's question, Microsoft's (or their forum moderator's) TOTAL contribution has been "Its your Interconnection speed" or "Start a new thread for more relevant attention".... inferring there is no problem.
Surely its in the moderators' interests to have a core MS technician address the problem which appears in manifest forums and blogs apart from this one? Are they not embarrassed at all? Even if the technician just said "Sorry, yes we screwed up but can do nothing about it in retrospect.", we would at least know where we stand, rather than live in a state of suspended anticipation. I can only assume that in the ludicrously litigious USA (yes I know we are following closely on their heels) this would open them up to demands for free upgrades to 7 or 8.
I venture to suggest that a free upgrade is now the very LEAST we should expect after such appalling indifference. Common courtesy demands.
(I get the same service from BT... they must have employed surplus MS customer service staff!)
Sad.