I recently had to reinstall my sound driver because my speakers weren't producing sounds they should have been, at times. After reinstalling it, the problem was fixed, but now I have another problem. If I plug in the headphones while sound is playing through the speakers, the sound does not transfer automatically from the speaker to the headphones, as it used to. Same problem vice versa - if I am listening on headphones, the sound does not transfer to speaker if they are disconnected. I get this error on some programs if I disconnect headphones while sound is playing:

"An audio device was disconnected or reconfigured. Verify that the audio device is connected, and then try to play the item again."

How can I get it to work like it did before, where sound automatically switches to headphones when they are plugged in, and vice versa when they are disconnected?

I'm assuming it has something to do with configuration.