If you are setting up a retro production suite, pair Cubase 5.1.2 with Windows 7, an RME Hammerfall DSP card, and a collection of early 2010s VSTs (like Sylenth1, Nexus, or Kontakt 4). You will have a low-latency, highly stable system that can still produce chart-ready music.
Searching for the legacy Cubase 5.1.2 update can be tricky since it is considered "unsupported software" by Steinberg. However, official download links for legacy versions are still maintained for users with original licenses. Where to Download Official Updates You can find legitimate update files for version 5 on the Steinberg Unsupported Software page Cubase AI 5 / Essential 5 : For these specific editions, a revised installer actually updates the software to cubase 5.1 2 update download