[ubuntu] using Virtual Box in Ubu 14.04

Hi, I want to try out Virtual Box. Reading up here: https://www.virtualbox.org/manual/ch01.html

I see it says I need the installation media for Windows to run it in Virtual Box.

I never had a CD or DVD. This Samsung Laptop came with a self installing Windows 8. 1, which installs itself on first start up. I keep Windows because I need it for some things, but I normally use Ubu, which takes up most of this HD. (I can't stand Windows!)

Is it possible to make Windows work in Virtual Box without having an installation DVD? Somehow link to whatever boots Windows??

Also, if you could recommend a good Android emulator. I heard of Genymotion, but it is not available in Ubu Software Centre

Thanks in advance for any tips!