Source installation (for 32-bit or 64-bit Windows)
 
1.Install Python: http://www.python.org/download/releases/2.7.3/
2.Install Numpy (optional): http://www.lfd.uci.edu/~gohlke/pythonlibs/#numpy
3.Install Setuptools: http://pypi.python.org/packages/2.7/s/setuptools/setuptools-0.6c11.win32-py2.7.exe
4.Install Pip: Start>Run... c:\Python27\Scripts\easy_install pip
5.Install PyYAML and NLTK: Start>Run... c:\Python27\Scripts\pip install pyyaml nltk
6.Test installation: Start>All Programs>Python27>IDLE, then type import nltk

# 
# script to register Python 2.0 or later for use with win32all 
# and other extensions that require Python registry settings 
# 
# written by Joakim Loew for Secret Labs AB / PythonWare 
# 
# source: 
# http://www.pythonware.com/products/works/articles/regpy20.htm 
# 
# modified by Valentine Gogichashvili as described in http://www.mail-archive.com/distutils-sig@python.org/msg10512.html 
  
import sys 
  
from _winreg import * 
  
# tweak as necessary 
version = sys.version[:3] 
installpath = sys.prefix 
  
regpath = "SOFTWARE\\Python\\Pythoncore\\%s\\" % (version) 
installkey = "InstallPath" 
pythonkey = "PythonPath" 
pythonpath = "%s;%s\\Lib\\;%s\\DLLs\\" % ( 
  installpath, installpath, installpath 
) 
  
def RegisterPy(): 
  try: 
    reg = OpenKey(HKEY_CURRENT_USER, regpath) 
  except EnvironmentError as e: 
    try: 
      reg = CreateKey(HKEY_CURRENT_USER, regpath) 
      SetValue(reg, installkey, REG_SZ, installpath) 
      SetValue(reg, pythonkey, REG_SZ, pythonpath) 
      CloseKey(reg) 
    except: 
      print "*** Unable to register!" 
      return 
    print "--- Python", version, "is now registered!" 
    return 
  if (QueryValue(reg, installkey) == installpath and 
    QueryValue(reg, pythonkey) == pythonpath): 
    CloseKey(reg) 
    print "=== Python", version, "is already registered!" 
    return 
  CloseKey(reg) 
  print "*** Unable to register!" 
  print "*** You probably have another Python installation!" 
  
if __name__ == "__main__": 
  RegisterPy()