To install SP1 immediately, click Open or Run, and then follow the instructions on your screen.Under System, next to System type, you can view the operating system. To find out which version you're running, click the Start button, right-click Computer, and then clickProperties.Choose either the 32-bit (x86) or the 64-bit (圆4) version of SP1 depending on whether you're running the 32-bit or the 64-bit version of Windows 7, and then click Download.Go to the Windows 7 Service Pack 1 download webpage on the Microsoft website, and then click Continue.
The easiest method is to use Windows Update.