How can i re-activate my 3.5mm port?

Hiya,
I am having some problems using my speakers as I have previously changed some settings on my audio devices. If i recall correctly, I doubleclicked the device name in the sound options on the startbar. I then clicked on the dropdown bar and selected the option to disable the device. But now that i want to re-enable it, there is no option to do so. Any ideas?

Using windows 7 by the way.