It's rather quixotic to expect an engine to find out a definite answer about this, especially when it's only on one computer. The computer chess world have access to top multi-processor engines that should be a couple times more powerful than what you used to analyse and still use opening books. There's a reason for this, and it's that engines have a limited scope, they will see up to a certain move, but if you take move 1, the amount of moves to let's say, move 10 is already very big, but opening theory can go up to 30 moves, for an engine to calculate all the possibilities of a 30 move game would take much, much more than 2 hours.
" 423 million moves"
That's about the first 7 moves analysed.
This is continuation of my thread about the strongest chess opening. I did further analasys with my reliable engine deep sjeng. I had it analyze the opening position for white for half and hour and it's conclusion after analyzing 423 million moves (235 k per second) to a depth of 21 ply is that strongest opening for white is d4 with a given score of .09 where 1.00= 1 pawn. I like d4 but haven't really studied it that much. I find this interesting because Most GM's I've seen use E4. The second strongest move for white is Nf6. Surprise? I though it would be a tie between e4 and d4, but my machine never even considered e4! It stopped liking Nc6 after 16 ply and 30 seconds.