How do I stop all the very annoying popups from Corel products from showing up on my desktop?

It seems like just about every day one or more popups show up on my desktop, usually in the lower left of the screen, trying to get me to buy a Corel product, in some cases for products that I already have!  The latest one, which popped up a few minutes ago, doesn't have a close "x" included so I can get rid of it.  I am about ready to go to Adobe products even though I have been using Corel Graphics suites since about version 3.