You mistakenly changed how the function keys work you can change them back easily.
Most laptops come with with multipurpose keys like F1 to F12 keys. These can be used for controlling multimedia, screen brightness toggle Wifi on and off etc.
They are very handy and good for productivity.
By default, if you are want to use the F1 to F12 keys for other functions as I have mentioned above you have to press the dedicated Fn key and the specific key. For example on my Dell latitude 7480 to increase the volume I use the keys Fn + F3 keys.
What most people dont know is you can invert the keys and use the multimedia functions without pressing the Fn dedicated keys
There are multiple ways of doing it, using the keyboard keys with your computer on, through the BIOS and using windows mobility center.
Revert / Invert Fn key using the keyboard
This is the easiest option and should work on most laptops, Inspiron, XPS or Vostro.
To revert the Fn keys to their default usage press Fn + ESC key.
If you accidentally inverted the Fn keys, you just press Fn + ESC key, then they will back to normal.
So you can toggle invert them that way.
If this fails you might need to change them in the BIOS settings.
Reverse the Fn keys from BIOS settings
To invert/ revert the Fn keys from the BIOS:
- Turn off the computer
- Now turn it on and on the Dell / HP logo press the F2 key to enter BIOS settings
- Navigate with the keyboard arrows to the Advanced tab
- On Advanced tab, using the arrows again select “Function Key behaviour”
- Then select either multimedia or function
- Save changes and reboot normally
The Fn Keys should have changed how they work depending on whether you set it on Function or multimedia
Change function keys in Windows Mobility Center
If you are using a dell laptop you might also be able to change it from the windows mobility center. You can find windows mobility center by searching on windows. Press start then search Mobility center.
Click on the first result and and a windows like the one below should open
Now toggle the options you want