Are You Ready?
After Microsoft ended support for the Windows Server 2003 operating system on July 14, 2015, the product stopped receiving: Security patches that help protect PCs from harmful viruses, spyware, and other malicious software. Assisted technical support from Microsoft. Software and content updates.

Now Microsoft announced that Windows Server 2008 and Windows Server 2008 R2 are approaching the end of their support lifecycle. This means that as of the dates in the table below there will be no additional:
• Free security updates on-premises
• Non-security updates
• Free support options
• Online technical content update

Customers who use Windows Server 2008 or Windows Server 2008 R2 products and services should migrate to Microsoft Azure to take advantage of 3 additional years of Critical and Important security updates at no additional charge and modernize when ready. For environments other than Azure, we recommend customers upgrade to the latest version before the deadline. For customers who cannot meet the end-of-support deadline may purchase Extended Security Updates to keep server workloads protected until they upgrade (some restrictions apply).

https://support.microsoft.com/en-us/help/4456235/end-of-support-for-windows-server-2008-and-windows-server-2008-r2