If you have decided you want the real experience, follow this guide:
The story of ArcaOS 51 begins with the OS/2 operating system, which was first released in 1987 by IBM and Microsoft. Over the years, OS/2 evolved into a robust and feature-rich platform, but its popularity declined with the rise of Windows. In 2001, IBM discontinued support for OS/2, leaving users with limited options for maintenance and updates.
To get the ISO, you must purchase a license through official retailers: ArcaOS 5.1.1 now available - Arca Noae
It supports 16-bit Windows and DOS software even on modern UEFI systems. Active Development: Arca Noae recently released version
Unofficial ISOs are prime territory for embedded malware or backdoors.