On July 14, 2015, all support for Windows Server 2003 will come to an end.
What does end of support mean?
After July 14, Microsoft will no longer issue security updates for any version of Windows Server 2003. If you are still running Windows Server 2003 in your datacentre, you need to take steps now to plan and execute a migration strategy to protect your infrastructure.
According to estimates, there are still millions of servers running Windows Server 2003.