Here are a few methods to resolve an error like this:
Try adding the server using domain name if the server is in a domain.
Try adding the server using name if the server is in a workgroup.
Check if you can ping the remote windows machine, from the machine where Applications Manager is installed. Try pinging with the hostname and its actual ipaddress.
If the server is in a DMZ, add the ipaddress and hostname in the <C:\Windows\system32\drivers\etc\hosts> file in Applications Manager server.
Check whether the RPC and WMI services are running in the remote machine.
In the remote machine, go to Start --> Run --> services.msc
Check whether the services Remote Procedure Call and Windows Management Instrumentation are running.
If they are not running, start those services and add them to Applications Manager.
Check the firewall settings and open the following ports required for WMI mode of monitoring.
Windows Management Instrumentation (WMI) (default : 445)
Remote Procedure Call (RPC) (default : 135)
DCOM for remote communication:
The server to be monitored uses a random port number above 1024 by default to respond back.
Connect to the target server and configure it to use a port within a specified range of ports (5000 - 5100). You can follow the steps mentioned in this link : http://support.microsoft.com/kb/154596 for restricting the ports in the target server.
Normally, opening at least a range of 100 ports is recommended. The same range of ports must also be opened in your firewall.
On the remote Windows computer, configure the firewall to allow remote administration. To do this, open a command prompt and type:
netsh advfirewall firewall set rule group="remote administration" new enable=yes
netsh advfirewall firewall set rule group="Windows Remote Management" new enable=yes
netsh advfirewall firewall set rule group="windows management instrumentation (wmi)" new enable=yes
From the AppManager host, use wbemtest to find the error message when connecting to the remote system.
Click on Start --> Run --> wbemtest
It opens up the Windows Management Instrumentation Tester tool. Click on the Connect button.
In the first text box (\\root\default) , enter the following path <\\hostname\root\cimv2>. Then enter the username and password under the Credentials tab.
If it works, then you would be able to access the machine only through the IP address. This may be due to some wrong entries in the <C:\Windows\system32\drivers\etc\hosts> file. Remove the wrong entries in the file and try again with the hostname.
If it still does not work, send the screen shot of the error dialog which comes in wbemtest to email@example.com