help with step 7 s300

i'm new with step 7 s300 and i hope anybody help me unlock individual blocks
regard

Use the search tool with the search terms "know how protect", this issue has been discussed in depth before including the legal issues involved.

If you're trying to unlock SFBs or SFCs, don't bother. It's not only illegal, you don't get anything useable out of it. These blocks are written in the machinecode of the microprocessor used in the CPU and may be different for a different CPU.

Regards,

thanks alot :
i know that there are program witch is called "s7 can opener" put i couldn't get it until now. could any one tell me how i get it pls
and i need to know how to prtect my FB i tried HELP as you siad and i found that i had to write code "know how to protect" in STL source FILE pls could some one tell me how.