I downloaded the beta (14 and 13) and it should have an installer\ uninstaller because when I installed 2.10 there were options for me to run it (small large fullscreen)I like that because zc wont run on my computer in fullscreen I normally run it in large but the beta only runs in small for me.
beta installer
you can add in a command line after the quotes in the shortcut properties of ZC and type in the syntax: -res 640 480 big
If you are using a laptop, laptops usually don't support 320x240 screen resolutions. It only can support at least 640X480 screen resolution.
Now that it's on a res 640 by 480 mode, is should be able to run in fullscreen.