Calculating FV. Where is my mistake? Is my error in excel or in using BAII? Problem statement: 
What is the FV of an investment of $10,000 which pays 7% interest, compounded monthly, for five years?  What is the FV is it's compounded semi-annually for 5 years? 
Using excel I have the following answer:

And using BAII texas:
I set:
Part a)  


Compounded monthly : P/Y=1 C/Y=12   
PV= -10,000
PMT=0 
I/Y=7
N=5
Ans: $14,176.25


Part b)

Compounded semi annually: P/Y=1 C/Y=2

PV= -10,000
PMT=0
I/Y=7
N=5
Ans: $14,105.99


Question: I can't found my error, if is in excel or using my calculator? Thanks!
 A: Under the assumption that the $7\%$ interest rate is a nominal rate of interest compounded monthly in the first case and semiannually in the second, we see that the effective monthly interest rate would be $j = 0.07/12 = 0.0058333$, and the accumulated value after $n = 60$ months is $$FV = 10000 (1+j)^{60} = 14176.25.$$  Your calculator is correct.
In the second case, the effective semiannual interest rate would be $j = 0.07/2 = 0.035$, and the accumulated value after $n = 10$ 6-month periods is $$FV = 10000 (1+j)^{10} = 14105.99.$$  Again, the calculator is correct.  You seem to have an error in your spreadsheet; especially since it seems to think that your future value is negative.  As to what that error could be, I have no way to tell since I cannot examine the formulas in the cells.
A: Your Excel formula is incorrect. You should have:
=FV$(\frac{0.07}{12}, 5*12, 0, -10000, 0) = £14,176.25$
=FV$(\frac{0.07}{2}, 5*2, 0, -10000, 0) = £14,105.99$
Remember: FV() in Excel is interest driven and is not "pure" math compounding. It assumes that interest ($7$%) is paid in equal tranches (e.g. $1/12$ per year for monthly payments or $1/2$ per year for semi-annual payments), which are compounded. FV() calculates $(1 + (\frac{7%}{12}))^n$ for period $n$.  In effect, it applies an effective annual rate.
What I call "pure" compounding would be $(1 + 7\%)^{1/n}$, where $n$ is the period number (e.g. $n =$ month $3$). Therefore, FV() will always be higher than "pure" compounding because effective rates end up being higher than nominal rates.
