How do I undo this?

I have a little problem…

You know this headphone connection on a laptop.

I have now plugged in my microphone cable.

But then I got on the desktop, "Always use" and I want to undo that now but I don't know how…

And you can save yourself such stupid answers with, well, bad luck or not my problem.

Do you have to format your laptop

Well, misfortune, but an ailment that doesn't overtake me.

Which means format "

Make new

And how do I make something new? Will my data be deleted or how?

Yes they will be deleted

Go to Sound Settings and then Properties.

Open Windows Settings and then click System / Sound. Choose another output device there.