I checked the source code and this error message is specific to the situation when you did not specify paths to installation CDs.
Since you are trying to enable SNMP on a Windows XP machine, you will have to get the installation CD (with corresponding service pack) and put it on a share, or (which is better in case of Windows XP) make sure it is available on the target device. Then in the Settings tab, in the "Specify Locations of OS Install Files", add the system and path to the installation folder.
If you decide to put the installation CD on a share, you will most likely have issues with installing the SNMP service using WMI. I would highly recommend using psexec instead. You may download psexec from http://technet.microsoft.com/en-us/sysinternals/bb897553. Then in the settings tab, select the Remote Access Type to psexec and provide path to the executable.
If the installation CD is located on the target system's drive, you may stick with using WMI.
One more note: the path to the installation CD has to be accessible from the target machine, and should be entered as you would access that from the target machine. For instance, if the installation CD is directly on the target machine in folder c:\install, the path you will add will be "c:\install".
Thank u very much your tips help me wonderfully.