Issue with notification bubble dialouge box thing ...

First off ... Merry X-Mas Wilders Security community !!

Now, to my problem, I've noticed that my notification bubble dialouge thing doesn't appear anymore. I'm talking about the dialouge bubble that (for example) Windows Security Alert displays if something is wrong. I can't see that anymore, but my speakers makes that *blok* sound whenever it supposed to be displayed.

My first noticing of this was when I manually checked for Windows Defender updates, where it always displays the bubble. Nope, doesn't anymore, but that *blok* sound is there. Neither does the Start Menu "don't have enough room for programs" notification thing appears. I've tried to find a display settings thing for this, but I can't seem to get it ...

This is what I remember of what happened ... :
-Updated programs (media, security, OS updates, etc.)
-Installed new HP printer
-Removed old Brother printer and its PaperPort stuff
-Tweaked startup with MSConfig, disabling WMP11 things, Java start things, and HP printer things
-Installed MSBA 2.01 for security purposes
-Stopped Desktop Cleanup Utility from running every 60 days

Also, does EasyCleaner and CCleaner registry cleaning have anything to do with this ... ? I really don't think so, but its the registry, so who knows ...

Anyway, thanks for your time and please help !! [Merry X-Mas !!]