If you own a netbook, a portable machine or even your PC which does not have an optical drive and you are waiting to install the latest Microsoft Windows 7 to install then Microsoft have allowed to do this job. You can have a Windows 7 USB/DVD download tool which helps you in creating a copy of Windows 7 to your USB or DVD disc.
In order to create a bootable DVD or a USB first download the ISO file and after that run the Windows 7 USB/DVD Download Tool. Once this operation gets successful you can install Wndows 7 directly from the USB drive or DVD disc. The ISO will be having all the necessary files combined in a single uncompressed file. With this tool you can easily copy the ISO to usb or dvd, To install Windows 7 now just insert your flash drive and run setup.exe from the root folder, same is the case with the DVD.
FOR XP USERS:
Note: Inorder to successful operation your machine must be loaded with Microsoft .NET Framework 2 or higher.
Also it must have Microsoft Image Mastering API v2, download here