Windows 10: Why does my desktop have a blank square in the lower right corner that appears and...

For a few weeks that box appears to me in that place and I have not been able to know why it appears, or how to remove it

:)

 

advertisements appearing a lower right corner of screen

advertisements appearing a lower right corner of screen each time computer is turned on. Anything that can be done to stop it?

 

Ads appearing on Desktop in lower right corner Windows 10

This is extremely frustrating. I have tried everything. Rkill, malware bytes, rouge killer, and probably many others. Nothing seems to work. There are these stupid ads that pop up on my desktop every so often in the lower right corner of the screen. I enclosed a screenshot. Sometimes the ads are different but always the same style of ad. What is this? How do I stop them?

I am on a dell laptop, windows 10 home edition, I use Firefox (not sure if that matters). I have emptied cookies and offline content multiple times, does nothing to stop it. I have literally tried everything I could think of except maybe casting a spell on it, which probably also wouldn't work. Please help.

 

Vibrating Mouse Arrow & Transparent square in lower right hand corner of screen

I have Windows 10. My computer was in sleep mode today for 2 hours and when I returned there was a transparent square in the lower right hand corner of my screen (right by date/time and notes) that
contains a mouse arrow. Meanwhile since this has appeared, MY wireless Microsoft Mouse arrow, is vibrating and disappearing. The pointer in the square changes from arrow to finger as I use my wireless mouse, which is making my life increasingly difficult.
I changed the batteries and checked settings. Everything seems to be as it should be. Can someone help me resolve this, please?