Unable to install Zorin onto my Desktop PC

Ok, can you open a terminal and paste in:

xrandr --newmode "1920x1080" 172.80 1920 2040 2248 2576 1080 1081 1084 1118 -HSync +Vsync

Then do

xrandr -q

Look for your graphics card name. It may be eDP or VGA-1 or HDMI-1 depending on what monitor you have and how it is connected.
Once you have the name, try to add the mode for 1920x1080 res
For Example on My Computer it would look like

xrandr --addmode HDMI-0 1920x1080

Replace the HDMI-0 with your monitor name