I'm trying to install Windows by using VirtualBox on mac, but the size of VirtualBox don't fit the size of my mac.
The window size is too small, how can I make it fit my computer?
By the way, I'm using Retina macbook pro.
You simply need to install the "Guest Additions". See the instructions on VirtualBox web site.
Once installed, reboot the VM and you will be able to resize the "window".