Windows 2003 Domain CA

I have a Windows 2003 domain CA.

It has certificates for domain controllers and some EFS certs for some users. The users are no longer with the organization and EFS was banned by GPO years ago.

We have people that use VPN to connect remotely but they connect to a Ciso concentrator, not the ISA box.

We are looking into migrating the CA but do not know what dangers we will run into. What danger am I in if I were to disconnect the network cables on this server?