Graphic card softwares and Display settings seems right for the question. That is precisely
where you would look for any brightness as well as contrast controls. Even most model lcd
monitors have some type of menu for manual adjustments. Display properties in the control
panel(not Windows control panel necessarily) may or may not have the type of setting you
would be most familiar with in that regard. But there should be some type of adjustments in
the Sony software package for display. These would be the two main areas to look for this.
You can also try right clicking on the desktop properties to see if there is anything there in
addition to the usual Windows options like refresh rate and resolution setting adjustments.