How do I adjust brightness on hannspree tablet

Go to Settings, Display, Brightness. If you have never accessed Settings, do a finger slide from the edge of the screen where you see the battery indicator symbol, and you should see an option for Settings (or a small symbol at top right that looks like a cog such as you see where the chain connects to the back wheel on a bike). Selecting/touching that will open the full Settings menu. Then scroll down until you see Display, touch that, and then find Brightness and touch that. Then you should see a slider. You should also see an option for Automatic brightness control. Some tablets come with this selected by default. Choosing it will cause the tablet to brighten when outdoors or in a brightly lit room, and to dim automatically when lighting is low. I have never liked it, but it works for a lot of people who are not as picky as me, and can potentially allow your battery to last longer. Good luck and enjoy your tablet!