Net Configuration Assistant doesn't open, created Listener in Net Manager but it isn't recognized when creating database Win 7
Try to run Netca "as Administrator".

The way Net Configuration Assistant and Net Manager create listener is the same - they both create configuration file - listener.ora. The difference is - Netca starts the service, but Net Manager is not. 

Also, you can check if your listener is running by looking into Control Panel - Administration - Services - something like "OracleOraDB11gHome1TNSListener".