Access premium skins and advanced settings [2].
The most reliable way to get a key is directly through official channels.
Without a valid , the software runs in an unregistered "trial mode" (typically 30 days). After that, skins revert to Windows default every hour, and most advanced toggles are disabled.
Maybe you truly cannot spend $10. Or perhaps you want to avoid any paid software. Here are free, safe alternatives that require at all.