How do I get rid of the black space on the left side of my screen on the desktop? 

Usually that is adjusted by using the buttons on the monitor to adjust the display properties of your monitor   Check the user manual for your monitor for instructions on using the On Screen Display.

Cheers, 

Hey,

To get rid of the black space on the left side of your screen, go to the Control Panel. In the control panel, click on Appearance and Personalisation, then select Taskbar and Navigation.  In Taskbar and Navigation, click Background > Choose a Fit > Change 'FIT' to 'STRETCH.