I usually originally install new games on C:, then move them after awhile to E: (external HD). Change the shortcuts, and voila! It does take a little time, but USB 2.0 is pretty quick.

This has worked with all my TW games, all the Call of Duty games, and all my Steam-generated games (10 or 12). I thought I might lose my saved-games, but no, everything moved over, and I could pick up where I'd left off in-game(s).

I've done this twice, in anticipation of reformatting C:... so far, so good.

But I admit, I've never tried to move such a monster as a 30 gig flight-sim.