When installing Windows Server 2003 on an HP Blade BL460c I received the following prompt box during the installation process.

In this instance I just had to cancel this dialogue box.

This Microsoft article gives the following outline on EMS:

“Emergency Management Services (EMS)  is a technology in Windows Server 2003 that supports remote management and system recovery for servers that are not accessible through an in-band connection.

An in-band connection is a connection between two computers that relies on a standard network, such as a local area network (LAN) or the Internet, and on standard remote administration tools, such as Remote Desktop or Telnet. You can use this type of connection to remotely manage computers only if both the local and remote computers are in a functional state and accessible on the network.

Emergency Management Services redirects text output to the out-of-band connection. An out-of-band connection is a nonstandard connection between two computers, such as a serial port connection, and is useful when a remote server cannot access the network or is not fully functional. Emergency Management Services provides a command-line environment for managing a server through the out-of-band port. The capability of redirecting text output is also known as console redirection.”

You can also perform an unattended EMS installation of Windows Server 2003 here is a Microsoft Knowledge Base article that outlines the steps.