Here is the step by step tutorial to install windows 8 from a USB flash drive. In order to do that, you will need an empty High Speed USB Flash Drive.
Instrunctions:
1. Download and install windows 7 USB/DVD Tool from cnet.com.
2. After downloading, double click on the downloaded file to run it. Follow the on screen instruction, and click finish button when installation is done.
3. Locate the windows 7 USB/DVD Tool on your desktop, double click on it. When the pop up box appears click on the browse buttonto locate the file, insert your windows 8 DVD installer and choose the ISO file
4. Select USB as the media type. You will see the USB device that you have connected to your computer. Choose begin copying.
5. Select erase USB Data when you are prompted.
6. You can now use it to install windows 8 on any computer capable of windows 8 OS.