The Management Server failed to establish a DCOM connection to the remote computer where you are trying to install an agent.
This can happen when there is a firewall or IPSec policy that only allows specific ports. Since DCOM uses a dynamic port range, you may not be able to remotely install an agent unless an exception is added to the firewall policy on the target agent. If you are not using a Host based firewall, you may need to add an exception to your network-based firewall between the IP Address or host name of the target computer (and all computers you want to remotely install an agent to) and the Management Server.
Add a firewall exception to allow all ports between the target computer and the Management Server.