Ok, I have maybe a ridiculous problem, but it's hell annoying.

I've got a new friend in excel and it's a useless vertical bar on the very right of the screen, just after the scrollbar. I have no idea why has this appeared and most of all - how to turn it off. Seems like excel didn't get the idea that I maximized the inner window. And here's the picture of my issue:



I can't move it, I can't turn it off and the most important - I can't move my mouse to the right to scroll the window, cause I get to this stupid useless bar.

Anything, please?