After the agent is installed for a specific WebLogic Server/Portal 10 domain, you cannot use the same agent binary files on the same server for a different domain. If you attempt to use previously installed agent binary files on the same server but on a different domain, the installation will fail. The agent associates a specific set of agent binary files with a particular domain on WebLogic Server/Portal 10.
To install the agent on a different domain, copy the agent distribution file (weblogic_v10_agent_3.zip) to a different location before you install the agent on the second domain.