Yosemite stuck on "Setting up" for hours I recently replaced the hard drives on my Mid 2010 Mac Pro, and thus had to reinstall OS X Yosemite.  (I went with Yosemite instead of El Capitan because, as the computer is destined to become a file server, I wanted native RAID support.)  I started the OS X installation around 5:30 PM last night; at 10:30 PM the computer was stuck on the "Setting up..." screen.  I know that OS X installs aren't supposed to take five hours.  Is the fact that I have the OS X install flash drive still inserted in the Mac Pro causing this?  Or is it something else?
Rebooting without the OS X flash drive inserted fixed the problem.