Last time I did a fresh Windows 7 install, I left it overnight and it was still searching for updates. Rebooted, left it another few hours and still searching. Then noticed I hadn't activated Windows yet (it was going to auto activate in a further 2 days at that point), so activated it and then the list of updates appeared within 10 minutes.
May just have been a coincidence, but it might be that the updates wouldn't show until it recognised Windows was activated?
Know I'm late to the party here as OP has already got the updates running, but just posting here in case the above helps anyone else looking into the same issue.