[Clipped the question and replies]

I installed Office 2007 after Office XP on a both an XP machine and on a
Vista machine.

Haven't experienced any problems yet flipping between versions of Excel but
Word 2007 is virtually a dud...with 2 versions installed...and perhaps with
only 1. The program crashes/freezes frequently and goes through a lengthy
re-confliguration if I use Word 2002 in between. Quite frankly I don't
believe Microsoft should be making the claim of compatibility until they have
fixed this.

I realize that you've made no mention of Word but thought I'd confirm that
Excel seems to work fine.