I was going through a bunch of files and renaming them when suddenly everything became sluggish, then just sort of stopped working. Then my sedktop background went black.
Now I can't open the start menu or any other windows thing like my computer ect, can't alt tab but I can open up other programs that have a shortcut on my desktop... Also my date/time at the bottom right of my screen seems to have moved an inch to the right and I can only see the edge of it now
Try just simply restarting your computer. If that doesnt fix it and you are worried something really went wrong, like a virus or something, then you can always just restore it to a previous date. This almost always works for me!!
edit: Although, I am not going to pretend to know very much about computers.... so maybe listen to others' advice before mine... Best of luck!!
Years ago, on my first computer, I decided to tidy up all my windows files. I moved all my .exe and .dll files etc. into new folders. My friends never let me touch their computers after that. Good times.