patterns.xml suggests: 

> If you want to change them, take care that Freemind 
> searches in you user home directory, 
> i.e. C:/My Documents/<username>/Freemind/patterns.xml

But this is wrong on recent versions of Windows, such as XP. The correct location is 

C:/Documents and Settings/<username>/.freemind/patterns.xml

Also, there is a note at the bottom of the patterns.xml file that comments out "Program with icon" style becuase "we have no undo." That must be an old note--I formatted a node with that style, then pressed Control-Z for undo--and it works perfectly.