I'm x32 I guess, how to find out?
It's typically called x86 or just 32 bit, not x32. According to wikipedia you can also use x86-32 instead but I haven't ever seen anybody use that. x64 is right but it's also commonly written as x86-64.
If you don't know if you have the 64 bit version of blender chances are you are running the 32 bit version. You would know if you needed the 64 bit version and remember downloading it. If you used the installer then you have the 32 bit version, there is currently no 64 bit installer.
If you're not on vista, you're using x32.
There are 64 bit versions of XP as well so you should still check.
You can tell which version you're running by starting blender and then going to help>about, so you don't have to mess around looking through the system properties. Some people with a 64bit os may still be running 32 bit blender. It will say win32 if you're running the 32 bit version of blender.