Microsoft released the first official service pack for Windows 7 today. This is an important update that includes previously released security, performance, and stability updates for Windows 7. SP1 also includes new improvements to features and services in Windows 7, such as improved reliability when connecting to HDMI audio devices, printing using the XPS Viewer, and restoring previous folders in Windows Explorer after restarting.

The easiest and safest way to install SP1 is using Windows Update service. If you use this, then your total download size will be 750MB for 32-bit Windows 7, and 1050MB for the 64-bit version. For this, you need to click Start, click All Programs and click Windows Update. In the window that opens, click "Check for updates" on the left. In the list of updates, you will see Service Pack for Microsoft Windows (KB976932), select it and click OK. Click Install updates to start downloading and installing the update. Enter your administrator password if prompted for the same. This method requires your computer to remain connected to the internet while the update downloads and installs.
Installing Windows 7 Service Pack 1 via Windows Update:

Go to Windows Update and then click on the “Important updates are available” link. If you don’t see this link, click the “Check for updates” on the left side, and it should show up.



You should see Windows 7 Service Pack 1 in the list, and you’ll need to check it (it’s unchecked by default).



Click the OK button, then click to install it, and then just wait. It’ll take a while to download, and once it finishes downloading, it’ll force you to reboot.



After some more time, you’ll be rebooted, and then you’ll see the dialog saying that it’s installed.



The second way is to download the from the Microsoft Download Center. Choose the version of SP1 according to your Windows version and click Download. Run this downloaded file to install SP1.

Windows 7 SP1 will help you:
- Keep your PCs supported and up-to-date
- Get ongoing updates to the Windows 7 platform
- Easily deploy cumulative updates at a single time
- Meet your users' demands for greater business mobility
- Provide a comprehensive set of virtualization innovations
- Provide an easier Service Pack deployment model for better IT efficiency

In order to download and install the Windows 7 SP1 you must currently have a Release to Manufacturing (RTM) version of Windows 7 already installed. If you have previously installed the Windows 7 SP1 Beta on your machine, you must uninstall the beta before installing the RTM.
Windows 7 SP1 is available for installation in the same languages made available at original launch of Windows 7.

Download:
Windows 7 Service Pack 1 x86
Windows 7 Service Pack 1 x64
Download Windows 7 Service Pack 1 DVD [ISO]