LOL! It's so simple to solve this.
Right click on the desktop and select 'NVIDIA Display >> [Monitor]'. In the menu that appears, select 'Screen Resolutions & Refresh Rates'. Move the 'Screen resolution' slider to the resolution you want (slide it to the extreme right for highest resolution) and select 'Highest (32 bit)' from the 'Colour quality' drop-down menu. Under 'Monitor Settings', enable 'Hide modes that this monitor cannot support' (though it should be enabled by default) and select the highest refresh rate from the 'Screen Refresh Rate' drop-down menu. Click on 'OK' or hit return (Enter). You're done. The screen will flicker and will stretch and fit to the corners of your monitor screen.
If, however, this doesn't work (though it should), then you will have to use the buttons provided either below the screen or on the right side of the monitor.
Hope this helped!