multi posting wasets peoples time and effort in that only the responses to
that individual post are seen

Being an OEM version - the COA is really only good for you anyway.  For OEMs
that come with computers - the COA (and product key) are normally on a
sticker on the machine itself.  Make sure that is not the case for you.  If
your Windows XP install is still functioning - simply get the CD Key
(product key - number you type in when installing Windows XP) from the
working installation and keep it with the CD in a safe place.  Assuming the
OEM that sold it to you is legitimate and sold you a legitimate copy - that
should be all you ever need.

Belarc Advisor (www.belarc.com) is an easy way to get that information from
your installed system... Assuming the OEM actually used that key when
installing it originally anyway - which is also something that could come
back to bite you.  Sometimes they will use their own volume license key to
speed up installation.

In any case - you should get the key of the installed system and put it with
the CD you have - making a backup copy of both the key and CD and putting
them someplace safe away from the other copy.