to get the latest service pack (SP2, SP4, ect) for your operating system, connect to the internet and run "Windows Update".
Windows 98
Windows 98 SE
Windows ME
Windows 2000 Professional with SP4
Windows XP Home Edition with SP2
Windows XP Professional with SP2
Windows XP Media Center Edition 2002 with SP2
Windows XP Media Center Edition 2004 with SP2
Windows XP Media Center Edition 2005
Windows XP Tablet PC Edition with SP2
Windows XP Starter Edition
Windows Vista
Windows 2000 Server with SP4
Windows 2000 Advanced Server with SP4
Windows 2000 Datacenter Server with SP4
Windows Server 2003 Standard Edition
Windows Server 2003 Enterprise Edition
Windows Server 2003 Datacenter Edition
Windows Server 2003 Web Edition
Windows Server 2003 R2 Standard Edition
Windows Server 2003 R2 Enterprise Edition
Windows Server 2003 R2 Datacenter Edition