My hdmi port. Not HP. Not ZorinOS. Is controlled by my Ctrl+F5 key.
Since Zorin is Ubuntu based
http://www.googlubuntu.com/
Sorry but that is the best I can do for you before I go to bed.
Best you search with your model laptop number and hdmi in the ubuntu search box.
Edit. If you get a male vga to male vga cable, It should work out of the box then. You will need to use your headphone jack with a external speaker for sound though,