Thread: Installing 32bit and 64bit OS on the identical PC?

I want to know how to establish 32bit and 64bit on the same PC? Can I divider off one hard drive and install disjointedly or will I have to install on two divide drives and disconnect the I don't want to employ at that time when booting up?
Edit: OS is vista BTW

With either XP or Vista on two divide drive you don't have to unplug moreover if you are dual booting both dentitions. To see each install unconnectedly you then unplug one to see Windows install onto the other along with a separate boot in turn record there.