Going to the Help menu on a computer running Mac OS X 10.6 Show Leopard will bring up a window that floats above all other open windows. Change Help Viewer’s always-on-top behavior with a simple Terminal command.
By default, Mac OS X does not treat Help Viewer like a normal application. An icon for it does not appear in the Dock, Exposé doesn’t acknowledge it, and it’s impossible to get it to sit behind another window. Even if it is not the actively selected window, Help Viewer remains on top until it’s minimized or closed. Needless to say, this inconsistency can be frustrating.
Back in 2009, MacYourself published an article describing this very behavior in Mac OS X 10.5 Leopard. It still does the same thing in 10.6, but readers report the fix in that article no longer works in Apple’s current operating system.
We’re not out of luck, though… there is a new fix for Macs running Snow Leopard. Just launch Terminal (Applications > Utilities) and copy & paste the command below:
defaults write com.apple.helpviewer DevMode -bool true
If you have a Help window open, you’ll have to close it before the change takes effect. After you do, Help Viewer will behave like any other application window. If for some reason you no longer want this modification, you can reverse it with the following Terminal command:
defaults delete com.apple.helpviewer DevMode