This isn’t a change to League itself, but a required security update to the connection between players and our servers. Service Pack 2 is no longer compatible with the latest security protocols. Unsupported systems might not be able to communicate with our servers and anyone still running Service Pack 2 won’t be able to log in or play the game. If you don't have a service pack installed, you'll only see your operating system version.

In the System: area of the General tab you'll find the operating system version and service pack level.

When the System Properties window opens it should default to the General tab.In the Performance and Maintenance window, click on the System Control Panel icon at the bottom of the window.If you're using Classic View for the Control Panel, double-click the System icon and proceed to Step 4. Click on the Performance and Maintenance link.

How do I know which Service Pack I have installed? Please visit Microsoft’s website for support here. If you're on a 64-bit OS, you'll need to upgrade to Vista or later. If you're on a 32-bit OS, you can download and install Windows XP Service Pack 3 for free here. If you are on an operating system using Windows XP Service Pack 2, check out the steps below to avoid an interruption of service. We’re announcing the end of League of Legends' support for Windows XP Service Pack 2, effective June 1.

Windows xp service pack 3