Answered
I converted a PowerPoint file to PDF and embedded .wmv files to the PDF. Now I have Mac users that cannot view the videos but Windows users can. I tried inserting the movie regularly and inserting it as "legacy content" (Acrobat 6 and later Compatible Media). What am I missing?
You'll need to convert the video into Flash Video (FLV) so you can use the Add Video tool in Acrobat 9 to embed platform-independent data (NOT in legacy mode). Also, if your Mac users are opening the PDFs in OS-X Preview, they won't see anything as it doesn't support video. They need to use Adobe Reader 9 or later.
To convert the WMV to FLV using the tools supplied with Acrobat you'd need Acrobat 9 Pro Extended, or an upgrade to the new Acrobat X Suite (which includes Adobe Media Encoder) - though there are masses of video converter programs out there from other vendors, many of which come with free trials.