Display Pictures Gone And Shared Documents Empty

The default display pictures on my user accounts are gone (E.g. Skateboarder and Rubber Ducky). They just became the chess pieces picture, but then again, when I try to change them, all I can select from are my own pictures, the default ones are gone.

Also, "Shared Documents" became "Documents". When I try to open it, I can only find subfolders such as "My Music" which are empty, every single file I saved there is gone. I think they are deleted from the hard drive now? Because I noticed the space has increased by a few gigabytes, without uninstalliung anything.