The Windows 7 USB / DVD Download Tool allows you to transfer the content of the Windows 7 installation sources to a USB device or DVD media. The tool is FREE and can be downloaded from here If you use Windows XP you must have at least the .NET Framework 2.0 or higher installed and you must install the Image Mastering API v2.0 prior installing the Tool.
Additional Information:
Microsoft Store: Windows 7 USB/DVD Download Tool
CodePlex: Windows 7 USB / DVD Download Tool