Unless there is a particular need to use a 64-bit installation for Excel, in particular, you're more likely to find problems you could otherwise avoid, especially with 3rd-party addins that don't work with 64-bit installations. When Office 2010 was released, Microsoft specifically advised against using 64-bit installations for that very reason - unless you believed the benefits outweighed the costs. The question, therefore, is why anyone should be 'forced' to use 64-bit Office.

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Cheers,
Paul Edstein
[Fmr MS MVP - Word]