Drag and Drop in Layers Not Working

Thank you again for your response. I apologize as I had no expectation at all that you make me a video. I am merely asking for a link to a video that has already been made. I have looked through dozens of videos but all of them involve complicated steps that do not apply to what I am trying to do:

***Change a grayish white background to plain white using a photo of a simple and solitary object***

I understand and appreciate your time constraints. If you are pressed for time can you please transfer me to a technician who can provide the steps necessary to change a background to white utilizing the least amount of steps?

I was able to successfully move the layers, however, I was not able to change the background to white. Using the 60 second video posted below and provided by Photoshop I performed the following steps:

1) Opened a simple photo.

2) Selected a new layer from the sub-menu.

3) Chose white from the color palette.

4) Chose Paint Bucket Tool and then clicked on my photo which turned it all white (just like the video)

5) Dragged and dropped the created layer under the main layer

6) Clicked flatten image which was supposed to turn the background in my photo white)

My photo looks exactly the same.

I don't know how to get any simpler than a 60 second video. Can you assist again please?

How to Change Background from Transparent to White in Photoshop CS6 - YouTube

I'm going to guess that your bottom layer is a background layer and not a regular layer. You need to unlock the background layer and turn it into a regular layer - in CS6, you can drag the lock icon to the trashcan... If this is not the case, post a screenshot of layers....