When I start Fallout 4 on my desktop it perpetually loads, I get the little circle and dot loading ad infinitum. (It never reaches the main menu). In order to close the game I have to log off my computer, because if I close with either ALT F4 or the task manager STEAM still considers it to be running, and my computer is slow and choppy.

The game opens and runs perfectly well on my laptop (a little slow, but that probably has more to do with the fact that the laptop is not well specced for Fallout 4).

Fallout 4 will not run on my desktop. My desktop is a Windows 7 Ultimate Intel I74790 Processor, NVIDIA Titan Videocard, 16gig 2500 ram. My laptop is Windows 10 professional Nvidia 950M I7 8gig RAM

I deleted all Fallout 4 files from my desktop, and copied the files from my laptop to my desktop and it still had the same problem.

Fallout 4 ran perfectly well on May 20, 2016, at 7:45AM, and will not run on May 21, 2016.

Any advice on how to fix this would be appreciated

Minor Edit
ALT F-4 actually has no effect whatsoever

Verify game cache integrity or whatever it's called from Steam, that might help.

Tried downloading FO4 a few days ago and the same thing happened to me, I have crappy download speed where I live so I'm not sure I guess the download just misses some files?

I deleted all the Fallout.ini or FalloutPrefs.ini, etc, and then I verified my game cache and the next time I ran it, it worked.

Lemme know if that helps!

Strangely enough I waited a couple of days, and it started working again. I honestly have no idea why it stopped working, or why it started again.