You accidentally downloaded the 64-bit installer. Double-check the filename for an x86 or 32 designation.
: Modern Unity Hub versions are strictly 64-bit. You will need to install the legacy editor as a standalone application rather than managing it through the Hub.
If you want to on a modern PC:
The definitive final version of the Unity Editor available for 32-bit Windows operating systems. Step-by-Step Download Guide
Go to the page via the official Unity website. Step 2: Navigate to Unity 5.x Unity 3d 32 Bit Download Free
Running older versions of Unity requires minimal hardware by modern standards, making it perfect for budget computers, older laptops, or educational computer labs. Minimum Specifications (Unity 5.6 32-Bit)
: 32-bit systems only recognize a maximum of 4GB of RAM. You accidentally downloaded the 64-bit installer
If your hardware limits your ability to run modern 64-bit Unity, consider alternative game engines optimized for lower-spec or older systems.
Or do you just need to that works on 32-bit systems? What operating system are you currently using? You will need to install the legacy editor
To download the 32-bit version of Unity 3D, follow these steps: