I swear that I read in "Star Trek: Enterprise: The Romulan War: To Brave the Storm", that by the year 2160, the NX-01 had shield generators; this notion is backed up by it saying on pg. 300 that the helm and shields are down, am I wrong?
Might want to try the TrekLit board... I'm no help because the first book was so bad I never picked up the one you're talking about.
You likely did better than I did, the first novel was so bad I stopped around a third of the way in. It's unusual for me not to finish a book I spent money on. Didn't the Enterprise crew spend the entire Romulan War hanging out on Risa?
I quit a third of the way into Beneath the Raptor's Wing. Enterprise's post-series novels are certainly the weakest of Pocket's Trek line. Which is such a shame, since I really enjoyed the novels set during the show, by Dave Stern. That's from the film they almost made, called Star Trek: The Beginning. Erik Jendresen said in interviews after the cancellation that he'd like to see his story novelized. I wish they'd done that instead.
Which is a shame, because I actually liked Kobayashi Maru. But whatever spark the books had were lost when Martin and Mangels split.
There is indeed a reference on p. 300 to both hull plating and shields being down. However, I can't find any other reference to NX-01 having shields in either Romulan War volume. It's conceivable that it could have had them by 2160, since we know that Vulcans and Andorians had deflectors in the ENT era, and Malcolm was working to develop them in "Vox Sola." But with only the one isolated reference, it could be just a typo.
^ In one ENT episode which took place in the future, it's said that Shran provided shield technology to Earth. I find that likely. His friendship with Archer would make him presupposed to considering humans to be allies and wanting to help them out. Spoiler: recent And Shran would be heartbroken to see what has happened recently between Andor and the Federation...
The evidence doesn't support it, but I wouldn't have remembered the words "shield generators", if I hadn't read it in the book.
Forgive the last message, lol. I was just frustrated that I could only find one reference in the book. Even if they had shields, they wouldn't have been that much stronger than polarized hull plating. I think, based on how badly the battle of Cheron was going, that they were just an extra defense that gave them more time to stay in a battle. If it wasn't for the Vulcans, Andorians, and Tellerites arriving when they did, Starfleet would've been defeated completely.