"a program that encrypts the client side files u want to Protect and decrypts it only after main.exe is runned"
-> shenanigans, you can copy the files anyway while the game is running
CRC to detect changes in files is shenanigans as well, because it can be circumvented too easily. I can't take any antihack vendor serious which is using CRC to check file integrity. They should use cryptographic hash algorithms instead (SHA256, for example).
Anyway... client side anti hack is either not secure or too intrusive to the system which creates instability. Best protection is on the server-side ;-)