..I heard it is possible to extract the code from a EXE. How can I protect my code? ..

Looks like the basic comments are that you can't protect your codes easily. I have never used encryption or Refox to protect my source code and lo and behold a reseller of mine decide to decompile my software and cut me out. Luckily for me they were very clumsy (they left my copyright info in the EXE and you can read the EXE in word and look for the text) and some of the customer's they sent the stolen software to didn't like dealing with them and sent me the evidence required. Of course, now I have to shell out $$ to a lawyer to sue them to stop them and collect damages (fat chance). Even if I never collect a dime I still feel it is up to me to protect my intellectual property.

No real advice from me -- Do what you can to protect your code (get legal advice in any business relationships), but at the same time don't lose too much sleep over it.

Kevin