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How to completely rebuild, repair, or refresh an existing XP installation without losing data, and without having to reinstall user software, reformat, or otherwise destructively alter the setup. by Fred Lang of Information Week.

-this I haven’t tried. I usually reformat and reinstall.
-question: can a slipstream include non-microsoft software? (I think a few years ago I noticed copies of XP customized to include other software, but I don’t recollect the software being pre-installed..rather, I think they were simply included in a sub-directory. You install them yourself. Saving a considerable amount of time searching for and downloading them.