Highlander,
You might try plugging them into your front panel for a test.
When it says "something has been plugged..", do you have a list where you can select headphones? (See screenshot below)
On your speakers:
Do the speakers require any drivers for themselves, or do they just plug into the jacks?
Do you have a relay cable connected from your computer's back panel microphone input to the speaker connection for the speaker's side microphone input?
Shawn