The version 5.5 release was a free update for registered Cubase 5 users, not a free giveaway of the entire program.
However, before you click on any mysterious "Download Now" button, there are critical things you need to understand about the legality, security risks, and modern alternatives. Cubase 5.5 Download Free Full Version
A completely free, professional-grade DAW for Windows that was formerly a high-end paid product. PreSonus Studio One Prime: The version 5
Downloading Cubase 5.5 full version for free is a bit tricky, as it is no longer available on the official Steinberg website. However, there are still a few options available: and modern alternatives. A completely free