Collection of tips to try, if radiant is not starting on Windows or preferences aren't saving.

*avoid non-english letters in paths to radiant executable and game engine
*run program _not_ from system disk partition (potential write permission problem)
*ensure that there is empty settings directory in radiant folder (settings will be saved there locally)
*run program as admin


**1st start can take a while: new fontconfig lib behavior is to parse all system fonts ^_^