Two boxes in the middle of my screen HELP!

[gianaznar]

I let my nephew play with my computer he ended up putting two weird boxes in the middle of the screen i cant get it out pls help. i attached a picture of what it looks like. your help is greatly appreciated!

 

[kemical]

Boxes? You mean the actual desktop picture?

If you right click on the desktop (anywhere) click personalize and from there you'll see how you can change the desktop picture.