Here's a quick little page with some notes of how to install python and dependent modules.  This was done on python 2.7

1. download and install python 2.7.x from https://www.python.org/downloads/  

2. install python in the default directory  c:\Python27

3. download the ez_setup.py script from  https://pypi.python.org/pypi/setuptools   (save this file in c:\Python27 )

4. open up a command prompt 

5. type   cd %PYTHON_PATH%

6. type   "set PYTHON_PATH=c:\Python27"

7. type  "python.exe ez_setup.py"

Easy setup is now installed ....  to install PySerial continue the following steps

8. type  "cd Scripts"

9 type  "easy_install pyserial"

C:\Python27\Scripts>easy_install.exe pyserial
Searching for pyserial
Reading https://pypi.python.org/simple/pyserial/
Best match: pyserial 2.7
Downloading https://pypi.python.org/packages/any/p/pyserial/pyserial-2.7.win32.exe#md5=21555387937eeb79126cde25abee4b35
Processing pyserial-2.7.win32.exe
creating 'c:\users\kwatters\appdata\local\temp\easy_install-ou4pyn\pyserial-2.7-py2.7-win32.egg' and adding 'c:\users\kwatters\appdata\local\temp\easy_install-ou4pyn\pyserial-2.7-py2.7-win32.egg.tmp' to it
Moving pyserial-2.7-py2.7-win32.egg to c:\python27\lib\site-packages
Adding pyserial 2.7 to easy-install.pth file
Installing miniterm.py script to C:\Python27\Scripts
Installing miniterm.pyc script to C:\Python27\Scripts
Installed c:\python27\lib\site-packages\pyserial-2.7-py2.7-win32.egg
Processing dependencies for pyserial
Finished processing dependencies for pyserial

Presto, you now have PySerial installed in python  (if all went well.)

start up python and you should see the following work properly

>>> import serial

>>>