In August 2002, Microsoft released an updated Windows 2000 service pack (which is a compilation of all bug fixes and enhancements).

Right-click on My Computer, go to Properties. At the top of the window, it will say Microsoft Windows (version) and the next line will say Service Pack 3 if you have it installed. Otherwise, it will say nothing.

If don't have SP3, you can get it from Microsoft's site here:
www.microsoft.com