Deactivating 'Extended Mail Merge' ~ Reverting to 'Standard Mail Merge'
Standard mail merge requires:
o Internet Explorer 6.0, 7.0, or 8.0
o Microsoft Word 2003 or 2007
o Microsoft Windows XP or higher(Windows 7 Not Supported)
Standard mail merge supports versions of Microsoft Word 2000 and above.
NOTE: Mail Merge & Extended Mail Merge use same templates:
Setup | Communications Templates | Mail Merge Templates
* Mail merge documents give you access only to the fields that are accessible to you via your page layout and field-level security settings. (Field-level security is available in Enterprise, Unlimited, and Developer Editions only.)
* Standard and extended mail merge don't support formatting from rich text area fields.