How to make a label be on the background?

[wysota]

you said discard label .. how?

Don't use it at all.

set the pixmap as the background brush for the palette of your window.. how?

Open up Qt Assistant, type in "palette" into the index tab and when results pop up (choose QWidget), find something related to "background".

Being a newbie doesn't allow you to not do research by yourself and expect others to give you complete solutions.