python at command prompt

[c3950ig at hotmail.com]

Hi,
I am python newbie and the command prompt is having an issue with
python. I installed python 2.4.4 onto my windows machine, opened a
command prompt window, and typed python to start the interactive mode.
Got the following error.

D:\>python
'python' is not recognized as an internal or external command,
operable program or batch file.

The following programs work fine
IDLE (Python GUI)
Python (command line)
PythonWin

For some strange reason, python is not recognized at the command
prompt.
Does anyone have any ideas as to why this is happening?
thanks,