I have purchased a Lenovo Thinkcentre desktop (second hand) from a friend.
The "windows XP professional" CD bundled with system is lost by the former
user.Now I have product key of that copy of Windows XP Pro but haven't the
original CD.I want to istall WinXP on my system.How can I get my copy of WinXP ?
What should I do ? communicate with "Lenovo" OR "Microsoft" ?
You may want to try Lenovo, at least that is where I would start. I sincerely doubt that Micorosoft will provide you with XP even if you have the product key. Keep in mind that support for XP expires April 8, 2014.
Also, check on your lenovo, even if they had included a CD, the original image may be stored on another partition. Again, I'd call them for support.