Under Hardy-Weinberg conditions, the frequency of the genotype `abcd` (in this particular order) is simply $F_a \cdot F_b \cdot F_c \cdot F_d = 0.24\%$.

If we don't consider the order, then we must ultiply the previous probability by 24. There are indeed 24 (=4*3*2*1) ways you can get this particular combination. The probability of `abcd` in any particular order is therefore $24 \cdot F_a \cdot F_b \cdot F_c \cdot F_d = 5.76\%$. 

You might want to have a look at the post [Solving Hardy Weinberg problems][1]


  [1]: https://biology.stackexchange.com/questions/58205/solving-hardy-weinberg-problems