I was having trouble updating the remote agent of a particular system after installing SP1 for Backup Exec 2010. I updated several other servers successfully, but this particular one would give me this error message:
"Error connecting to the remote server. Ensure that the server is available, has WMI enabled, and is not blocked by a firewall.24"
The firewall service was disabled so I knew that wasn't the problem. This computer is not a domain computer like all of our other systems, so I thought that had something to do with it. However after doing some research it seemed like that wasn't the issue.
I followed the work arounds in this post: https://www-secure.symantec.com/connect/forums/2010-remote-agent-installation-error
However all of the services that needed to be running were, and the GPO's mentioned had the proper user accounts associated with them so that didn't help either.
The fix ended up being really simple, as they often are once you find them. I noticed the time was off by one hour on that system. I checked the time zone and it was set to Eastern instead of Central. Once I had the time zone set correctly and the clock was accurate, then I was able to push the remote agent successfully.
This problem irritated me for a few hours so I wanted to share this solution to possibly help others that are getting the same error message.