[spacenick88]

Why on earth would you want to install 32 bit Python 2.7 if you already have 64 bit Python 2.7?

[lmz]

32 bit C extensions?

[SonOfLilit]

One example that comes to mind is that you use an extension library that has Windows binaries available out of the box for x86 but not for x64.

[osullivj]

Yes - extensions. Particularly 32bit .xlls.