One approach is to check the configuration of your WebSphere instance.
Ensure that WebSphere is running.
Examine the values for the following installer fields:
WebSphere Virtual Host (PS_IBM_VIRTUAL_HOST in the state file)
Application Server Name (PS_IBM_APPSERV_NAME in the state file)
Use the WebSphere tools to check the configuration to make sure it matches the values you are entering.
Try again.