Can someone please tell me....

[shortliner]

....how to get rid of the wide blue borders that appear down both sides of the screen, and reduce my viewing area - when I try to see a posted picture, the only way to see all of it is to save to desktop and view from there, which is, frankly, a PITA! I can not see any way of getting the picture to scroll sideways either. The problem isn't help by the "posters details reducing the size further. I've enclose a screengrab to show what I mean
TIA
Jack