I used to export audio, and then use Windows Media Player's options for playback to do the half-speed thing.
I long-ago switched to using some inexpensive software (The Amazing Slow Downer) that was something like $49-$50, and it allows all kinds of control over playback speed - without changing pitch, plus you can loop sections and all that sort of thing, which I always found great for figuring out some of the speedier parts of people like Keith Emerson or Allan Holdsworth.
But I think the Windows Media Player playback options do work, in any case.
Bob Bone