c++ - What is the bit size of long on 64-bit Windows?

Not to long ago, someone told me that long are not 64 bits on 64 bit machines and I should always use int. This did not make sense to me. I have seen docs (such as the one on Apple's official site) say that long are indeed 64 bits when compiling for a 64-bit CPU. I looked up what it was on 64-bit Windows and found

• Windows: long and int remain 32-bit in length, and special new data types
  are defined for 64-bit integers.

(from http://www.intel.com/cd/ids/developer/asmo-na/eng/197664.htm?page=2)

What should I use? Should I define something like uw, sw ((un)signed width) as a long if not on Windows, and otherwise do a check on the target CPU bitsize?