You can download the original C&C for windows and there are instructions on how to get it to run on Windows XP.
Unfortunately the 'how to get it to run on XP' doc seems to be broken at the moment[1]. Using good old google cache you can view the doc as HTML though. Click here and then click on view as html:
(Click 'Continue Reading' below to see the install doc if you can't be bothered with the above)
[1] Amusingly the 404 error for the missing document itself has a 404 error since the server can't find the 404 error document it's supposed to serve.
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