I’ve seen a number of notes and blogs on the Internet on how to create a bootable USB Key to put Windows Server 2012 and/or Windows 8 on it and they all probably work well, but just about the simplest and easiest method I’ve used is to leverage the Windows 7 USB/DVD Download Tool FREE from the Microsoft store. As I ready myself for a number of Windows Server 2012 events and Hands on Labs, I needed to create a number of bootable USB keys for attendees and this is just the most absolutely pain-free way to do it. No manual command-line tools, just a quick app to get this several step process done neatly and cleanly. Installing Windows Server 2012 or Windows 8 from a USB key is one of the fastest ways to do it, and this is a simple way to make it happen quickly.
So what do you need? The Windows Server 2012 or Windows 8 .ISO file, a 4 GB or greater USB key (8 GB or larger is nice but not required), download the tool, run it from Windows, and the tool does the rest!
Click “Next”
Click the “USB Device” button
Click the “Begin Copying” button
The app will check to see if there is enough space on the target USB device and prompt you to erase it. Choose the “Erase USB Device” button
It makes sure you REALLY want to wipe your USB key, and away it goes, formatting and copying the files to the USB key. After about 10 or 15 minutes, you’re done.
If you have a bunch of bootable USB keys to create (like I do), you’re able to just click the “Start over “ button and run it again.
Enjoy!
http://blogs.technet.com/b/bobh/archive/2012/09/04/the-simplest-was-to-create-a-bootable-windows-server-2012-or-windows-8-usb-key.aspx