Yes, Windows 7 32 bit. If you system isn't capable of 64 bit extensions, however, I would guess that your machine is rather old, and you might want to consider upgrading and/or rebuilding it before getting Windows 7.
I'm curious, what exactly are your system specs? Pepper is right, if you don't have 64-bit capable hardware you may have a very unpleasant experience with any version of Win7. We're talking pre-Athlon 64's here circa 2003. Is your system 2002 or older???