[Python] Python PySerial, How to Open Serial Ports?

I'm trying to run this example program from the PySerial Documentation for opening serial ports. Source: http://pyserial.sourceforge.net/shortintro.html I tried running the code in both python version 2.7 and 3.4 but still get same error.

>>> import serial
>>> ser = serial.Serial(0) # open first serial port
>>> print ser.name # check which port was really used
>>> ser.write("hello") # write a string
>>> ser.close() # close port


I get the following error after running the second line of code:

Traceback (most recent call last):
File "<pyshell#2>", line 1, in <module>
ser = serial.Serial(0)
File "C:\Python27\lib\site-packages\serial\serialwin32.py", line 38, in __init__
SerialBase.__init__(self, *args, **kwargs)
File "C:\Python27\lib\site-packages\serial\serialutil.py", line 282, in __init__
self.open()
File "C:\Python27\lib\site-packages\serial\serialwin32.py", line 66, in open
raise SerialException("could not open port %r: %r" % (self.portstr, ctypes.WinError()))
SerialException: could not open port 'COM1': WindowsError(2, 'The system cannot find the file specified.')

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