Just like Microsoft ended support for Windows XP last April, this July 14, 2015, Microsoft will no longer issue security updates for any version of Windows 2003. This effectively signals the end of Windows 2003 in the enterprise.
If you're using Windows Server 2003, you most likely have already moved or will have moved off of Windows Server 2003 by July 14. But if you are one of the laggards (and, according to Computerworld, there are "millions" of laggers) you are highly advised to start planning, and execute, an upgrade plan for your Windows 2003 Servers before July 14. After that date, Microsoft won't issue critical updates and patches for Windows Server 2003—making it a prime target for viruses and malware.
Significant for ASNA customers
This is a significant issue for ASNA customers because after July 14, 2015, we'll no longer be able to issue fixes or updates for the Windows Server 2003 platform. Given the exposures it provides for viruses and malware, we can't afford to keep it running in our network.
If you don't yet have a plan for migrating off of Windows Server 2003, visit Microsoft's Migration Planning Assistant soon to help you plan your migration.