Blackberry Enterprise Server hanging on Intialization

First, restart the BB services...

Start, run, services.msc

From BB's website:
The correct order to start the BlackBerry Enterprise Server services is detailed below:
BlackBerry Router
BlackBerry Dispatcher
BlackBerry Controller
All remaining BlackBerry Enterprise Server services

The following is the order in which to stop the BlackBerry Enterprise Server services:

BlackBerry Controller
BlackBerry Dispatcher
BlackBerry Router
All remaining BlackBerry Enterprise Server services

Note that if the Controller fails to start and displays a 5003 error, stop the DNS Server service, start the BB Controller Service, start DNS Server service.

Recreate the activation code, try the enterprise activation again.

If that doesn't work, delete the user in BB, reset the services as above, try the activation again.

Note 2: If the phone displays an error about contacting the administrator during the enterprise activation, backup the phone using Desktop Manager, wipe the phone, power off, take battery out for 30 seconds, replace, power on, restore the phone using the Desktop Manager, repeat the Enterprise Activation.