To be honest Windows 7 updates can be catastrophically slow. It's having to check dependencies and versions on thousands of files at times to see what fits. As a general rule I'll start setting up a new machine in the offices a week ahead, disable any auto power off settings and let them churn away.
It is possible for Windows Update to corrupt itself or die entirely. There's Microsoft instructions on doing a reset. In the end it just takes time.
Just in case it all comes together and you get a big list, only allow it to install 10 at a time. It gives Windows less ammunition for a major screw up, and makes things easier traceable when an update gets naughty.