Cant welcome you, since you been around a while, so Ill star with a hope I can help
There are two causes for this a change in screen resolution or malware/virus.
First if the disarray bothers you, this software will do the trick Stardock.com - Your Edge In Software
If you are concerned about the problem, I would:
Run a full scan antivirus.
Download and make a full updated scan with malwarebytes
Check the driver for your monitor and graphics.
Run an SFC scan.
If everything is negative, it was probably a one shot deal, with a multitude of reasons (but most likely the reason were caused by change in screen resolution)
Thanks for asking us for help, after all the help that you have given others.