Should be under Display in the Control Panel.
But usually people change the screen resolution to their liking, so what you can do is right click on the desktop, choose properties and you should be able to change the size there. (Usually a decent size is 800x600, though most monitors are on 1024x768). You can access this through Display icon too.
But usually people change the screen resolution to their liking, so what you can do is right click on the desktop, choose properties and you should be able to change the size there. (Usually a decent size is 800x600, though most monitors are on 1024x768). You can access this through Display icon too.