Finder Preferences allow users to change the sidebar, alter how searches work, show file extensions, configure label names, alter what devices show up on the desktop of a system and control the behavior of Finder windows. You can access Finder Preferences either using the Preferences menu (under the Finder menu) with the Finder as the active application or using the Command-, keystroke.
There are a number of reasons I’ve seen people want to disable Finder Preferences, such as controlling user experience and easing support of the user experience for OS X. To do so, send a boolean ProhibitFinderPreferences key to com.apple.finder as TRUE (and kill the Finder):
defaults write com.apple.finder ProhibitFinderPreferences -bool true; killall Finder
To change it back:
defaults write com.apple.finder ProhibitFinderPreferences -bool false; killall Finder