Windows Media Encoder which is available from Microsoft also includes a few handy utilities that allow you to easily trim Windows Media Files, change the metadata of an existing file, split and combine streams in multi-bitrate files and create and edit Windows Media Encoder profiles (.PRX).
Head to Microsoft's Windows Media Encoder page and click on the Windows Media 9 Encoder link to download the utility.
Microsoft's Windows Media Encoder page.
Install the program. Now listed in your start>programs will be a folder called "Windows Media" with another folder called Utilities. Located in the Utilities folder is the Windows Media Profile Editor. Click on the Profile Editor to run it. From here you can Import and modify my Custom profiles and save them as your own.
One warning though. Choosing these options will greatly increase the encoding time of videos. The improvement in the quality is usually worth it. If you are encoding something that you need quickly and aren't so concerned with squeezing the most quality out of it, uncheck the option.