Problem loading Python mode

[bar tomas]

Hi,
I'm using Emacs 22.3 on Wind XP.
When I open a Python file (with py extension) I get  the following
error warning:

File mode specification error: (file-error "Cannot open load file"
"python-mode")

I have checked in the lisp/prog-mode folder and there is a file called
python.el.

The only modification I have done to the init.el file (in .emacs.d) is
to paste the followiing lines at the end of the file for org mode :

     (add-to-list 'auto-mode-alist '("\\.org\\'" . org-mode))
     (global-set-key "\C-cl" 'org-store-link)
     (global-set-key "\C-ca" 'org-agenda)
     (global-set-key "\C-cb" 'org-iswitchb)


     (global-font-lock-mode 1)
     (add-hook 'org-mode-hook 'turn-on-font-lock)


Do you know what may be wrong?
Many thanks.