Be warned ! Microsoft Office 2010 32 bit edition only works with ACT! 2011.  If you have an earlier version of ACT!, you have to either upgrade ACT! or downgrade Microsoft Office to 2007 or 2003.

Also please note Microsoft Office has to be installed before ACT! does.  This allows ACT! to “see” that Microsoft Office exists and will add the necessary connections.

Here is the article from Sage.