As mentioned, you can still use Spine on a 32-bit computer but the highest version of Spine you can run is 3.8.99.
Please note that 64-bit Windows has been available for 20 years, which is a very long time for computers. Even quite old computers should be 64-bit by now. Microsoft itself has discontinued support for all versions of Windows 7 and does not offer a 32-bit version of Windows 10.
