Hello, how are you?
My name is Paloma B., I am very happy to be able to try to help you in the best possible way.
This is an open community, whenever you need you can share the problem so that possible repairs are suggested.
Could you share your computer model? Press Windows+R, type msinfo32 and click OK, when opening the info window, send me a printscreen please.
If it is a Dell notebook, this setting must be in the BIOS of the computer.
When accessing it by pressing the F2 key as soon as you turn it on, you will have the Keyboard settings in the menu to configure the lighting as you wish.