Do you have Genuine Windows 7 Key but lost the DVD to install it from? Now you can download the Genuine official ISO image of the Windows 7.
REMEMBER YOU MUST HAVE GENUINE Win 7 KEY for the version you are installing.
Various web-based online storefronts and retailers (e.g. Digital River) sell Windows 7 licenses, and to fulfill the orders, the online stores host and provide digital downloads of Windows 7 setup installation files in the form of ISO image, which can then be unpacked and extracted, or used to mount on virtual drive and burnt to a DVD media disc to clean install Windows 7 on a blank PC or upgrade a system from existing operating system.
SOURCE 2: [for updated SP1 ISO image]http://www.mydigitallife.info/official-windows-7-sp1-iso-from-digital-river/
Check POST# 2 for details and clickable links