Greetings,
I’m totally new to Zbrush, so this may really be a dumb question to most of you. My install of Zbrush doesn’t start with the startup window, as shown in the first video. Instead, I get a scene already loaded with the big red ball, which I have to get rid of every time I start up the app. Is there a way to initialize ZBrush so that I can get that regular window with the four different options on it? My guess is, I may have to reinstall Zbrush, which I’d rather not do if possible. thanks
You’re describing the current default scene in 3.5. You do not have to “get rid” of the ball–just pick another ztool and it will change. Right now you cannot change the default scene for ZB 3.5–it will probably be restored in a future release if history is any guidance. 
You can make some adjustment for preferences, such as layout of the shelves. To “unlock” the interface, go to preferences -> custom UI and select “enable customize” When finish, turn off “enable customize” and then go to preferences -> config and select “store config” to save you layout.
More details here: http://www.pixologic.com/docs/index.php/Changing_the_Interface_Layout
thanks kerwin, your help is much appreciated. 