Dont waste your time running Chrome Os via parallels or vritualbox, it kills the real purpose of chrome os.

you just need:

1- a 4 or 8 GB usb memory card
2- Free program called Image Writer for Windowsand
3- a Chromium OS USB Image (go to the pirate bay and do a search)
4- a computer that can boot from USB

Donwload the Chromium OS USB Image just 300 megs, and you will get a 3 GB .img file
run Image writer and select the image (Chromiumos.img), select the USB drive letter where you
will install the OS, then push the "write" button, once is done, you just need to put your usb in the computer you want to test and boot from USB normally you need to push F12 key to boot from USB
default username: facepunch password: facepunch, if everything goes fine it will load in just 10 seconds or less depending on the speed of your USB memory (less info)