Just installed Premiere Elements 12 on my 64-bit Windows 8.1 Pro laptop. I have Apple Quicktime 7 installed. MPEG-4 is not offered on the Share/Publish menu. Why? Your documentation says that Premiere Elements supports MPEG-4. How do I eneable it as an export option?
Premiere Elements 12 does have opportunites to export your Timeline content with the .mp4 file extension.
(But... just in case note..remember the .mp4 is only a wrapper/contained format...so consider the file compression along with its file extension (wrapper/container format).
Please check out
and the MP4 presets there.
Mobile Phones and Players
Apple iPod, iPad and iPhone
and the MP4 presets there
Two points that you may not be aware of
a. Under Publish+Share/Computer/ there are more choices that just Adobe Flash Video, MPEG, and AVCHD. The rest of the list can be accessed by using the thin scroll bar to the right of the list in order to scroll through the complete list.
b. In your export choice area, look for an Advanced Button. Under the Advanced Button/Video Tab and Audio Tab, you can customize the export settings.
Please let us know if we have targeted your question.