If Windows Update is not offering you the option to install the service pack, see KB 2498452. You can use our step-by-step instructions or, if you prefer, let us do it for you.
The best way to ensure you get Windows 7 and Windows Server 2008 R2 SP1 is by turning on the Automatic Updates feature.
It also provides ongoing improvements to the Windows operating system by including previous updates delivered over Windows Update as well as continuing incremental updates to the Windows 7 and Windows Server 2008 R2 platforms based on customer and partner feedback. Windows 7 SP1 helps keep your PCs and servers on the latest support level.