HP Pavilion and restore cd's

Ok....... a friend gave me a HP pavilion 511w.
It needed a new hard drive........so i bought a new one from newegg.
Anyway, i contacted HP to order a set of restore disc....they told me they were no longer available.
The windows XP COA sticker and # is still on the side of the pc.
I realize i could buy an oem copy of XP from newegg......but the restore cd's would have been much cheaper.
will the number on the COA sticker work with any XP oem disc?
Or will it only work with the original restore disc?
I realize i could install linux on it but most people are too novice to use it.
Any suggestions would be much appreciated?