Still getting ioBit notifications after uninstalling Driver Booster Free

[MAF]

I got a new Acer laptop in Jan 2019. Due to a host of issues, I was advised to use Driver Booster to upgrade drivers.  I'm not sure if it helped, but recently, it threw up a notification that did not have a GUI control for banishing it.  I forgot what the notification was, but not something I was interested in.  It persistently blocked out a good portion  of the lower right quadrant of my screen.  I didn't have a lot of personal free time remaining that day and I was really trying to accomplish a particular to-do.  This ad essentially eliminated any hope of doing so, as I had to spend the rest of the time figuring out that I couldn't get rid of the ad, then uninstalling Drive Booster.

Since then, I've still gotten an ioBit notification that my browser has left traces that could compromise my security.

How is this even possible when I've erased Driver Booster?

How can I completely erase all traces of this software?