I am going to take a different approach to your question.
Assuming that it has been used before, the only component that would possibly have a decreased life expectancy is the Hard Drive, since it the only moving part. All other components do not wear out, as does the Hard Drive; although they can, of course break. Run the chkdsk function on your computer and then defrag; if all is ok just enjoy. Any software can be downloaded again, if problems develop.
I do wish you the best of luck with your computer.