@flyburg: not entirely true. Again it might be option dependent, but at least the version of an FCOM (we use a company tailored boeing provided one) i have available (effective date april 27 2010) states regarding the predictive windshear system:
Predictive Windshear Inhibits
During takeoff and landing, new predictive windshear caution alerts are inhibited between 80 knots and 400 feet RA, and new warning alerts between 100 knots and 50 feet RA. These inhibits do not remove existing predictive windshear alerts. If a warning/caution event occurs before those boundaries, it will remain on the display and the complete aural callout will be annunciated.
That sounds pretty much the same as the 777 information posted by Fil.