To output individual frame grabs, use Publish & Share/Computer/Image. This will output a single still image of the frame you're currently on.
The program used to also have a Filmstrip feature, that would output your entire movie as individual frames. It may be buried in the Advanced Publish & Share features, and maybe someone on this forum is able to dig it out.
If you wanted a jpg file for every frame in the video, then, using Premiere Elements 11 Windows,
and under the Advanced Button/Video Area for the preset selected...in the Export Settings Dialog, be sure to put a check mark next to "Export As Sequence".
Before hitting "Save" to initate the export, I would be sure to set the Save In for a folder located on the hard drive and created to receive all these jpg files.
More later if needed.
This is so helpful, thank you so much!