I've seen some people here say that First Contact changed the timeline, and thus Enterprise takes place in a tdifferent timeline than TOS and TNG onwards.
But if that's the case, how can you explain that Q-Who requires the Borg to know about the federation, which they only find out about because of the transmission sent in Regeneration. How can events in an alternate timeline affect events in the "original" timeline?
Depends on which one makes you sleep better at night.
To me it is all one timeline up until Star Trek 2009
. Dramatically, it is more satisfying a structure.