Microsoft released Service Pack 1 (SP1) for Windows 7 earlier this year and it includes several security and performance related enhancements for Windows 7 all rolled into a single installer.
The easiest and quickest way to install this service pack on your Windows 7 computer is using Windows Update. However, if you have two more more computers running Windows 7, you may download the standalone SP1 installer from microsoft.com and apply it to all your computers even in offline mode.
There’s a third option as well. You may order Windows 7 SP1 on a DVD and Microsoft will deliver it to you via snail mail. They won’t charge anything for the media but you’ll still have to pay shipping charges that vary depending on your country. For instance, if you are in North America, the shipping cost for the DVD is around $6 while Windows 7 users in India will have to pay around $11.
Obviously, a very small number of people would probably take the DVD option but if you are one, pull out your credit card and click your region name - Asia, Europe and Africa, North America or South America - to begin the order process. As you may have noticed in the screenshot, you may order up to three Windows 7 SP1 DVDs in a single transaction.