Hello Peter from the Moon,
Thanks for posting your concern here.
On your screen, selectAction centeror Notification center on the most right side of the taskbar, and then move the Brightness slider to adjust the brightness.
If this answers your question, please let our Community know by marking this post as an answer. Otherwise, don't hesitate to respond to this thread if there’s anything else that needs to be addressed.
Kind regards,
StevenK