At some point in the progression of the Windows operating system life-cycle, software developers started building their applications to come to the front, or some function to become the active function in your workspace when they reached a certain point in loading or carrying out a function.
Let me see if I can explain that a different way in case I'm too brief up top.
You set something to work (your HP Solution center scanning a document) and you go back to what you were doing - typing a document in MS Word. What happens is that the scanning software gets to a certain point where it is "processing" and has a function button that says "cancel".
The Developers program this screen to come to the front of your windows and be the active screen, and since you don't realize this is happening because you are typing a sentence, you hit the space bar in your progression of composing something, which activates the "cancel", and now your HP software thinks you canceled the scan. It stops, and you have to start all over again.
Let's do another example.
You are working on a document, you click on the Outlook button to get it going. All through its opening process - who KNOWS what it's doing at that moment - it forces itself to be your active workspace, and there is nothing that it's done that needs your attention... it just wants to be in front! and so you have to keep clicking back to MS Word (or your browser, or notepad, or whatever else you were doing).
I remember when this switch happened. I was in grad school when this shift in thinking happened.
Windows gives you the option to have multiple applications working/open/active at the same time.
thanks! I like that...
I know you are there, scanner, because I made you work! I am ok with you finishing your job and then waiting quietly in the background until I'm ready for your product.
So why, oh why do you think you need to come to the front and remind me that you exist?
Why do you do it?
...because you think I'm stupid and need you to make decisions for me?
*edited to add "Windows" because this does not happen on my Mac.