Apple Corp. has adopted a fairly aggressive marketing approach to making its Safari browser available to users of the Windows operating system, even when the browser isn't installed on the computer to begin with.
First understand that many users of Mac and Windows use iTunes and Quicktime. Those software programs are updated regularly through the Apple Updater. The updater will update those products, but while its doing that, why not just go ahead and install Safari 3.1? Or in the case of a Windows OS, Safari for Windows.
That's what is popping up and if the user just clicks the install button without reading what is being installed without thinking about it, then Apple has won another "user" over to its Safari browser even if the user never uses it. Understand that Apple is trying to promote its browser and other products by any means possible but this may appear to be a little underhanded to quite a few people.