One of the problems IT professionals run into in the modern world is that software and operating systems that run perfectly fine stop being supported by their vendors. When NT 4.0 was replaced by Server 2000 the benefits to upgrading were obvious and necessary. Server 2003 itself was a good Server OS and many people chose it even after 2008 was released. Sadly Server 2003’s day is almost done.
As of July 14, 2015 Microsoft will no longer support Server 2003:
Windows Server 2003 support is ending July 14, 2015
What does end of support mean for you? 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 datacenter, you need to take steps now to plan and execute a migration strategy to protect your infrastructure.
I know the first instinct of many IT pros is to simply give Microsoft the middle finger and keep running Server 2003 anyway. Being that it is now a 12 year old operating system regardless of if you stay with Microsoft or not it is wise to think about migrating. I personally find Server 2012 to be a very good Server OS with many features that Server 2003 did not support, but frankly if you’re running Web or File Server this may be the time to finally jump ship and start building more of your infrastructure on Linux.
Whatever you do take the EOL of Server 2003 seriously. At the very least verify your backup routines are running properly and your security infrastructure is where it should be.
You can learn more here: https://www.microsoft.com/en-us/server-cloud/products/windows-server-2003/