Okay, here's the update, if you're curious. I ran Recuva (what a neat program!!) and it didn't find it either. So, really, I guess I can live without it.
Here's what I think happened: about 3 weeks ago I installed Windows Service Pack 3 for XP. It darn near destroyed my computer, with crashes and non-responsiveness, etc. I then un-installed it, but I am still suffering issues from it. One of my biggest problems is that I can no longer run a virus scan on my entire computer without the computer crashing. I've even gotten rid of Norton and gone with AVG just to see if it was a Norton issue, but it's not. I can run partial virus scans on the most important areas, and my computer's not infected, but anyhoo. Now I think maybe it wasn't C Cleaner that deleted my HP program, maybe it happened in the SP3 debacle.