Bernie wrote...
I'm dealing with only 4 specific columuns in a worksheet. If the cell in one
column is YES (O4) and the two other columns have dates greater than 5 Jul
08, then I want to show "GO" in the fourth column otherwise it would reflect
"NO GO". *I should know this but haven't worked with Excel for about a year
and forgotten too much.

If the Yes/No(/Other?) were in A3, the two dates in B3 and C3, and the
result in D3, then use the following formula in cell D3.

=IF(AND(A3="Yes",MIN(B3,D3)DATE(2008,7,5)),"GO"," NO GO")