See
http://support.microsoft.com/?kbid=284896 "'Most recently used' list
missing from File menu and 'Recently used file list' option unavailable
in Office XP and 2003".
joscar wrote:
For Word and PowerPoint, I cannot activate the feature that allows me to
quickly pull up "recently used files". I am unable to place a check next to
the required box and, in fact, the line is "greyed out". thanks so much for
helping!