What is this popup? Should I be worried?

Are you using any software from PC Tools, Spyware Doctor for instance?

As for PC Tool? I'm using Registry Mechanic and Privacy Guardian.

Smart Update appears to be a PC Tools device for updating their software.

That's exactly what it is. I started Registry Mechanic and manually hit the Smart Update button and got the same update box.

Thanks Butrflynet!

I'd give you a ribbon for answering the question but I accidentally hit the Start a Discussion button instead of Ask a Question button for this thread.

Will a basket filled with dog biscuits suffice?

Only if you put a big bow on it!

Glad it was something relatively innocuous.