Yes, as Eduardo says, the discontinuation of support for 32-bit systems was announced a year ago to give people plenty of time to upgrade their OS or system, or to make sure that they did not purchase a new 32 bit system.
This only affects Windows users, as Mac OS X is 64 bit.
http://www.archicadwiki.com/Discontinued32BitSupport
I sympathize that you apparently purchased or upgraded to Windows 8 32 bit after Graphisoft had made this announcement, which was designed to help make sure that people only purchased 64 bit OS in preparation for the release of 17. Worse, I sympathize for the hassle of upgrading to a 64 bit version of Windows after just reading that Microsoft's only upgrade path from a 32 bit OS to 64 bit OS requires a complete reinstallation of all software (and presumably all license activations - so if you do this be sure to de-activate all software first!).
One of the forum moderators
AC 27 USA and earlier • macOS Ventura 13.6.6, MacBook Pro M2 Max 12CPU/30GPU cores, 32GB