I ran into problems installing DPM agent on a few of my servers over the network through the DPM admin console. In this case I had to manually install the DPM agent on the servers I wanted to protect. Here are the 4 steps:
1. Locate the 2.0.5820.0 folder on your DPM server here in:
%systemroot%\Program Files\Microsoft DPM\DPM\Agents\RA\
The 2.0.5820.0 folder is here and will have folders i386 and amd64 in it. If you are installing on a 64bit server use the installer from the amd64 folder otherwise just use the i386 folder.
2. Copy to this folder to the local %systemroot% drive on the server you want to protect. I created a folder in on the server I wanted to protect to make things easy called DPMagentinstall
for example c:\DPMagentinstall
3. Open a command prompt. If this is Windows 2008 server be sure to open the command prompt with elevated privileges. Then type: CD c:\DPMagentinstall\DpmAgentInstaller.exe YOURDPMserverFQDN
EXAMPLE: DPMAgentInstaller.exe DPM01.mydomain.com
It will then let you know that your server requires a restart if it was successful.