Yep, you are going to need to upgrade your computer to 64 bit.
He doesn't have to upgrade his computer, just his OS. Computer hardware has been 64 bit for a long time now.
I would like to repeat, and emphasize, a previous request I made to have GC3 report in a window before going down any time it is started on a system that does not meet the minimum operating criteria. A 32bit operating system is certainly one case of many.
Knowing why it won't run on one's system is much better than having someone screaming and cussing about how bad your product is.
Better yet, in this case, would be a warning when someone is trying to actually install it that the OS doesn't meet the requirements. No point in spending the time trying to put it on your system in the first place if it's not going to work.