+ AA6YQ comments below
VB =VisualBasic… I just figured it might be something with that… in my ignorance, but it works now…
+ Thanks, Dave. Evidently, installing VB re-registered MouseWheelControl.ocx . There's a simpler way to re-register a component, if this happens again.
+ The question now is "why did MouseWheelControl.ocx become un-registered?"
+ When did this problem first appear. What changes to you hardware or software did you make around that time?
+ I suggest checking the Windows Event Logs for signs of hardware or software failures.