Wallpaper black, icons gone, everything in harddrive left

Hello,

Today when I logged on to my computer the screen was stuck on "preparing your desktop" for a good minute, it never even shows that message but today was different. When I finally got on the wallpaper was black and most of the icons on the desktop were gone. The taskbar had also lost most of the programs pinned to it except "internet explorer" and "windows media player"

Ad I look around the whole "explorer" was pretty empty except for the default stuff. For example all of my pictures were gone and there was nothing in the "downloads" folder. But as I got to the local disk everything was left. Most programs however were reset in some way. For example i had to log in again in order to use programs like " Google Chrome"

I've searched around a bit but nothing too practical has come up.

Help would be much appreciated.