Problem with sound settings

So i just changed my sound settings(i dont know how) And now it is so.
I have headphones as a laptop normal speakers(usb headphones) and when i unplug them i dont hear anything. If i plug my speaker system to headphone jack the speakers doesnt work. so can someone help me getting my settings correct?

In the Desktop view (press Windows key and D at the same time), if you don't have a speaker icon at the bottom near the clock, search for "turn system icons on or off". Next to the Volume icon, set the Behavior to On, and click OK. Now it should appear in the lower right corner.

1. Right-click on the speaker icon and choose Playback Devices.
2. Click on Speakers, right-click and set to Default Device.
3. Click on Properties and then on the Levels tab. Make sure the speaker icon doesn't have a red circle in it. If it does, click on it to get rid of the red.
4. Finally, adjust the Speakers/Headphone slider to the right, maybe to around 85.

That should solve your problem.