Most "keygen" executables contain Trojans or spyware designed to steal your passwords or encrypt your files.
a step-by-step guide for building a Rescue USB drive. Macrium Reflect Serial Number
If you have purchased a valid serial, here is how to enter it: Macrium Reflect Serial Number
If you have already purchased Macrium Reflect, your serial number is typically stored in three places: Macrium Reflect Serial Number