Hello there,
Microsoft is ending support for the Windows Server 2003 operating system on July 14, 2015. After this date, this product will no longer receive: Security patches that help protect PCs from harmful viruses, spyware, and other malicious software.
If you don't have an installation medium then it might be difficult to install these older versions of the servers.
Hope this resolves your Query !!
--If the reply is helpful, please Upvote and Accept it as an answer–