License Key

• What is a license key?
• Where do I get my license key?
• What does a license key look like?
• That's a long license key. How do I enter that?
• Where do I enter the license key?
• What's the difference between a license key, activation code, serial number, and registration key?
• My license key didn't work. Now what?
• My computer crashed and I have to install Windows and all of my software. I don't have my license key anymore. Now what?