Hi George,
Great Question.
In my research, it doesn't appear to have been tested across the 64-Bit
operating systems as of yet.
However, it appears the next version of Visual Studio will have some
support in the 64-Bit Processors.
http://www.cfdreview.com/newsoftware/03/11/01/2110215.shtml
Check out the 64-Bit programming page as well
http://msdn.microsoft.com/visualc/using/building/64bit/default.aspx
Cheers,
Tim Macaulay
Microsoft Corp.
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