Windows95 was still very much a DOS based OS and no doubt the emulator that you are referring to was a little program called DOSBox which we have and can run win95 on. You may also be surprised to hear that earlier versions of windows could actually run on a variety of architectures.

Now XP was microsoft's effort to remove any and all dependance from DOS and chose to build it for x86 only. Hence no ARM or powerPC versions were ported.