HOW TO: Create a bootable USB flash drive in Windows from an ISO (Manually)

Summary:
A bootable USB flash drive can be used as an alternative to booting from CD or PXE on a enterprise network.

Prerequisites:

• ISO file that you want to boot from (Linux, Windows, etc.).  In the example below I will make a bootable Windows 8 Installation CD USB drive.
• USB Flash Drive: Verify that it is large enough to hold the entire contents of the ISO file
• 7-Zip: Used to extract the .ISO file to the USB Flash Drive. [DOWNLOAD]

Preparing the bootable USB Flash Drive:
1. Insert a USB Flash Drive into a Windows 7 or Windows 8 client.
2. As an Administrator launch the Command Prompt. (Windows Logo + R, type: cmd.exe, Enter)
3. In the Command Prompt type:

ATTENTION: Replace '#' with the DISK number of the USB Flash Drive.

diskpart
list disk
select disk #
clean
create par primary
select par 1
active
format fs=fat32 label="Win8ProInstall" quick
assign
exit

4. It may be necessary to remove the USB Flash Drive and re-insert it.
5. Locate the file windows8pro.iso on you local computer (or whatever the ISO you have is called)
6. Right-click on the file windows8pro.iso and locate the 7-Zip context menu option.
7. From the 7-Zip context menu select the option "Extract files...".
8. In the "Extract" dialog enter the drive letter of the USB Flash Drive and click "OK" to begin extracting the files.
9. Once the extract process completes, eject the USB Flash Drive. Test the drive to ensure that it is ready for production use.

Alternate Instructions - Especially for Linux based ISO's:
Although I've had less success with creating Windows bootable USB drives with another tool called UnetbootIn - it can create bootable USB drives without the need for entering data in a command prompt.  Personally I've found this tool to work much more reliably with Linux bootable drives.

UnetbootIn Project Homepage