Service Pack 1 (SP1) is the first service pack for Windows Vista, released by Microsoft on March 18, 2008. It includes updates and improvements to the operating system, such as new features, security enhancements, and bug fixes.
There are several ways to check if Service Pack 1 is installed on your computer. One way is to go to the Control Panel and click on “System and Security.” Under “System,” you will see a line that says “Windows Edition.” If it says “Windows Vista Service Pack 1,” then SP1 is installed.