By default, the Command Center installs the version appropriate for the OS. To force 32bit install on 64bit Windows using the Command Center make sure "Verbose Install" is enabled. This will cause every installer to show all prompts including the 32/64bit install option.The Vebose Install option is on the "Command Center" setup screen.

Aha ! :) Thank you very much scook, that's very helpful ... you seem to be all knowing.