Hello,
You all guys are right. I should not try to upgrade software at each store without paying for license or FEF code since this is their hard work income. Absolutely right that I asked stupid questions about POS and wasted your guys time. I am extremely sorry about that.
Hi Ray,
I don't know how to crack a system, but I think that I may be able to give you some advice.
1. As a store owner, the POS system is something you should protect, not something you should crack, because the POS system brings convenience to your businesses, and also provides protection to your money.
2. If you can crack the POS system easily, then someone can crack it to steal your money easily too.
3. If you are an engineer, trying to crack the POS system, you should find a proper forum to ask your questions, there are a lot of resources around the Internet, but KEIL's official forum is not the place to ask questions about cracking.
4. Cracking a system, is a very professional job, you need to learn a lot of things; and you better to learn that things all by yourself; if you just use some tools provide by someone else, then those tools might hurt you with some hidden malicious features.
5. Assuming that FEF code is encoded store number, shows that you don't know much about System and Software, so you are not good/evil enough to crack the POS system.