Windows Installer loops when I start Windows XP

I'm not trying to install anything, but when the boot ends and I get the desktop the Installer immediately tries to "finish" installing Roxio Media Manager, part of BlackBerry Desktop that I have never used.
But it can't complete and whether you say OK or Cancel it just starts over.

I can kill it with Task Manager, but what I want to know is:

Where is it getting the idea it has to install anything? I don't know where the
list of "things to install at next boot" resides. Any idea? I could patch it out.
Is it someplace in the registry, perhaps? I've searched for Roxio there and removed all words Roxio but that doesn't help.

 

Is it on startup, try and kill its startup.
CCleaner is a good program to have and it allows startups to be deleted that and many more options.

 

Wow. Thanks!
I figured I could get a good answer on this forum.
I had run CCleaner since the problem arose, but I hadn't checked all of its options.
The Registry Integrity scanner was what solved the problem.