This probably happened after you went thru setup, activated your wi-fi, or plugged in a network cable, then put in your user name and password, etc..etc... and as it went to the next phase of "setting up", you got the "just a moment" error... (p.s. this is a normal error, happening with lots of people)... I have found this to be a problem with Hardware Identification, during setup.
Here's what I have done, to make it happy and finally get past the "just a moment' stuck screen.
1. disable your Wi-Fi or unplug your network cable if so setup.
2. remove any USB device, keyboard, mouse, printer, usb drive, etc...
then reboot computer and see if it gets past the "just a moment" screen... it worked for me on a few laptops, I have setup for various offices..
Once it boots, if it does, and you get to your desktop.. Then turn on you wi-fi and have it "configure" itself.. make sure it works... ok... then reboot computer... if that works... then connect any USB devices you have, one at a time, wait for them to setup, then reboot after each one is configured.
that worked for me...
good luck
-sapphire