: Added support for forest trusts , allowing different organizations to share resources without merging entire infrastructures. ISO Availability and Installation

Back in 2003, you’d likely be burning these files to a physical CD. Today, you are more likely to mount them in a virtual machine or use a bootable USB. Virtual Environments

: While most 2003 installs were IA-32, it also supported x64 and Itanium (IA-64) architectures. You can check your version

Windows Server 2003 extended support ended on July 14, 2015, making it a legacy operating system

Windows Server 2003 End of Support (EOS) FAQ - Virtual Machines