Hi, I hope somebody can help me. I just downgraded my OS from Window 10 to windows 7, and after that, the brightness of display cannot be adjusted anymore. IT's too dim. F4 and F5 is not working as well.
Please post the model computer so we can give a more specific answer.
Also, check to see that you are using the correct drivers for that OS. You can find drivers for your system here.
If the system is under warranty, please contact me privately. Be sure to include your personal information (name, address, telephone, email) and your computer's service tag number in your message. Thanks.
If there is no warranty, then you could contact our Out of Warranty team to get a quote for a paid service call -