Permanently disable syntax highlighting in Notepad++ for all file types

Peter F's answer actually helped me figure out a way that worked 100%. Yes, removing everything in "stylers.xml" does disable syntax highlighting. However, it still make opening big text files very slow for those that were recognized as a certain filetype. The syntax highlighting is gone but you could see in the bottom left of the application that it was still recognizing the language.

In %AppData%\Notepad++ I saw the langs.xml file there and deleting the offending languages there actually made opening and navigating the big files fast again. Now, it no longer recognizes those languages and shows up as "Normal Text."

Sorry for the delay in getting back to you guys--I had a problem with my account and I couldn't log in for a few days.