I can't adjust the screen brightness on my laptop?

I have a lenovo something or other (got it as a christmas present, not sure of its actual make) and just today when I turned it on, the screen brightness was a bit low so I hit the fn button and up arrow (the keys to up the brightness on it) and it wouldn't move up from the first notch up. I tried manually adjusting the scroll bar, tried going into the display settings, nothing that I could find would work. Does anyone at least know what's wrong if not how to fix it?

Also, if it's any help, it went to sleep while updating yesterday and a guy at the computer ship had to take out the battery, but it would adjust after that, only now after I've shut it down does it fail to change.

You didn't say but you were trying to adjust the sliders in the control panel/ power settings?

Press the fn key then press f5 or f6 key. Like: press fn+f5 to up brightness, press fn+f6 to down brightness.
If this proses is not work you contact lenovo customer care or lenovo sells center.