Here are some 32-bit CPUs (IA32 = Intel's 32-bit architecture) to help clarify.
K6 / K6-2 / K6-3
Athlon or "K7"
Pentium / Pentium 2 / Pentium 3 / Pentium 4
It's a pretty safe assumption that you're not running an AMD Opteron (Very new CPU that can do both 64-bit and 32-bit modes). If there's any doubt, you can open up a console and type cat /proc/cpuinfo to get information on your processor. Look for the model name.
"Floating in a dream-like state, I am the emporer of a parallel universe." --Arch Enemy
My xorg.conf file