Blank Desktop and User Files Deleted

I logged onto my home PC earlier today and everything was fine, but I leave soon after to get some food and when I return about an hour later, my desktop is completely black and all my icons have been removed except for the Recycle Bin. Also my W8 tiles, many have dissapeared along with all of my taskbar icons besides the windows icon. When I tried to go to any folders from my user account (documents, desktop, downloads) I get this error message:
"C:\Users\tinyJ_000\Documents is unavailable. If the location is on this PC, make sure the device or drive is connected or the disc is inserted, and then try again. If the location is on a network, make sure you;'re connected to the network or internet, and then try again. If the location still cannot be found, it might have been moved or deleted." I tried to do some research on this and nothing has worked, when I went to "C:\Windows\System32\config\systemprofile" there was no Desktop Folder there. I am on Windows 8.1. I have not restarted my PC yet as people have said resetting it could cause loss of files permanently. I also have logged onto other users on the PC and they are working fine so I believe it is just this user. Please help and thanks in advance!

Is there a USB stick or Windows DVD that you can boot, using any 3rd party utility, hopefully undelete and copy off any critical data files? In other words, only one user has seemingly lost desktop and data files? When you left for food, was any kind of PC cleaner/PC fixer utility or antivirus/antimalware super-scan set to run in your absence? Windows Updates automatically doing its thing? Do others have access on that user account? Perhaps, accidentally doing something that lead to this? I'm straw-grasping. I'm trying to remember what causes can lead to such a bad effect upon a user account.

Lets hope you did not catch one of the Ransomware virus. You can go through the Malware check-up over at READ & RUN ME FIRST Malware Removal Guide (incl. spyware, virus, trojan, hijacker) - MajorGeeks Support Forums

Sounds like an active desktop might have been activated.
Download the file bellow, run it, allow adding to registry and restart.

Malware scan is also recommended:

Emsisoft Emergency Kit
Kaspersky Virus Removal Tool