I may have misunderstood you, are you trying to make your LINE IN work with headphones or speakers?
Line In is for a microphone, if I am misunderstanding you I apologize.
Also if you could give us some specs about your computer, This little app here Speccy - System Information - Free Download will help with that.
i have three connector and speaker and microphine and line in
i'm using line out for speaker (the green one)
i'm using the MiC for the microphone (the red one (pinkish))
and the line in or the blue one i need to change it form line in to line out (like the green one ) in the old days on XP when you connect a device it show you a dialog box to chose what is the device (line in , Mic ....)
and there for i need to connect a head phone to the line in
I don't remember ever being able to change a Line In to a Line Out in Win 95. They're hard-wired for particular circuit paths.
Just go to Radio Shack and get a line splitter for your Line Out jack.
The cannon sound is in your sounds control panel. Go to Control Panel, select "Hardware and Sound" and, under the third header, "Change system sounds."
In the Classic View control panel you just click "Sounds" and go to the third tab.
Hit the "Windows" header at the top of the list with your mouse key once, and then scroll down the list with your Down Arrow key. You're scrolling down all possible sounds Vista OS plays. Any of the basic system sounds like "Low Battery Alarm" or "Device Disconnect" that doesn't say "Windows..." in the sound scheme is what you're looking for.