I think you will find that tramp is enabled by default. If you do:
Mx customize-apropos Customize (regexp): tramp
('Customize (regexp):' this is an invitation from emacs), you will see the two variables listed (at least I do in emacs 23), something like:

If you set the tramp mode to "off", save for future sessions and restart emacs. tramp will no longer load. I believe that you can simply disconnect it in the current session so that you can check it, but this does not always work with setting variables, although it should do something like tramp included in the standard emacs distribution.
I no longer have emacs 22, but something like this should work for this as well.
Peter Hart
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