There aren't. For most apps, producing 32-bit-only is preferable. If you're going to produce 32-bit and 64-bit, you should make available a stub installer that

There aren't. For most apps, producing 32-bit-only is preferable. If you're going to produce 32-bit and 64-bit, you should make available a stub installer that downloads the right one or an installer with both in it because most users have no idea if their OS is 32-bit or 64-bit. Mainly because they don't even know what that means.