software for new hardware acting up

I have Windows XP home version. For some months (since the official stop of Microsoft maintenance? I think less than that) I frequently get a pop-up about new hardware found, although there is no new hardware attached. I dismiss it and get a warning from the lower right-hand corner of the screen, which also I dismiss. What could be causing this? I should perhaps add that Microsoft appears still to be updating my PC on a daily basis.