Sometimes you just have to give it the time it needs, and at other times, it can be two or more running apps or processes that are kind of waiting on each other.
I always go to the Task Manager (ctrl+alt+del) and end processes/apps I know are non-essential and safe to stop, and I'd say in 7 out of 10 cases, the process that was "frozen" continues and finishes up.
If everything else fails, you just have to bite the bullet and reboot, but try a soft reboot prior to a hard one.
Microsoft is conducting an online survey to understand your opinion of the Technet Web site. If you choose to participate, the online survey will be presented to you when you leave the Technet Web site.