Using PRX files
A PRX file contains encoding settings for a video, much like the presets in Microsoft Expression Encoder. In fact, PRX files are considered to be presets. You create PRX files by applying encoding settings, such as bit rate and video size, to your video in Windows Media Encoder, and then saving those settings to your hard disk. If you created and saved specific settings in Windows Media Encoder, you can also make those settings available to Expression Encoder, which means you won't have to recreate what may be a complex and specific set of encoding settings that you created previously. You can apply a PRX file either by browsing for it on your computer and then loading it into your job, or by putting your file in the Expression Encoder JobPresets folder so that it will be visible in the Presets panel.
To browse for a PRX file
Click the Presets tab. If you can't see the Presets tab, on the Window menu, click Presets.
On the Presets options menu, click Browse for preset.
Browse to the PRX file that you want to load, and then click Open.
To save a PRX file as an Expression Encoder preset
Locate your PRX file and put it in the JobPresets folder, which is located in "C:\Users\<username>\Documents\Expression\Expression Encoder." Once you put the PRX file here, it appears on the User tab of the Presets panel, and you can apply it to your media just as you would with the standard Expression Encoder presets.
For more information about using presets, see Apply presets.