why making it the hard way
depending on windows you use , be smart and use teh build in tcp/ip filtering from windows
put a block range on it if he keeps returning , and you got yourself a nice ban (you dont exist anymore for him)
here is how to do it in case you dont know how to use the windows iptables
its hard in the beginning , but easy at the end and good to
enjoy reading :d (with a lot of screenshots to explain it step per step)
Greets From PowerChaos