touchpad does not communicate during setup

Hey there mbachemist,

It sounds like your mouse pointer can move but you cannot tap to click when you're not logged into your account. This is expected behaviour per:

Magic Trackpad: About the Tap to Click feature

http://support.apple.com/kb/HT4331

Tap to Click is a user specific preference, just like your Desktop picture or Screensaver. If you log out of your account, you won't be able to tap to click at the logout screen. In addition, when you start up to the Install DVD or Apple Hardware Test, the Tap to Click feature won't be available.

You will need to click the track pad when not logged into a user account:

Click

Press down anywhere on the Multi‑Touch surface to physically click or double-click. Or, with “Tap to Click” enabled in System Preferences, simply tap or double-tap the surface.

https://www.apple.com/magictrackpad/

Thank you for using Apple Support Communities.

Cheers,

Sterling