The thing is with the brightness slider. it's not there where it should be.
I've already installed the driver for my display monitor. & graphic chip.
It' an Intel NUC.
what else should I do ?
Are you a laptop? If so, are you using the driver(s) provided by your laptop manufacturer?
Download, run, and ATTACH the results of this utility (using the PAPERCLIP under the toolbar):
Then, an Intel support engineer can assist you.