For security reasons, recent versions of Java may block unsigned Java applets (websites )from automatically running by default. And since you have installed Netbeans, the latest JDK might have got installed and overwritten your old Java version.
You need to change the Security level of your Java configuration by following the below steps:
Click on the Windows "Start" menu in the lower-left corner of the screen --> "Control Panel" --> "Programs" --> "Java".
In the "Java Control Panel" window that appears --> Click the "Security" tab.
If there is a "Exception Site List" section in this window, click on the "Edit Site List..." button --> Click the "Add" button --> Type in the web server location for the Java applet like "http://www.google.com/" --> Click the "OK" button --> Click the "OK" button.
If there is no "Exception Site List" section in this window --> Slide the "Security Level" indicator from "High" down to "Medium" --> Click the "Apply" button --> Click the "OK" button.
Click OK in order to save the changes.
Close ALL of the open windows. You must completely QUIT the web browser or this workaround will fail.
When I connect an external microphone to the jack, it is not working. I can see it in the "Sound" tab, but the levels is very low. I have tried with several microphones.