How to make computer screen full size??

[Louise07]

Hello, my very unhelpful toddler pressed something on my laptop and now the desktop screen and internet screen has gone narrow. This only happens on my husbands user, if I log onto my own user it initially goes narrow when laptop is loading up, but when it is loaded the screen automatically goes to normal full size. Have tried to restore to a previous date but there doesn't appear to be any previous dates saved so cannot try this. Any idea what my toddler may have pressed and how to rectify it? TIA.

[AlBags]

Log in as him.
In system tray by clock, there is probably a utility to change display setting .. Correct setting will be theree somewhgere.
If you cannot see there, r-click desktop and select display .. find the correct tab to change display.