This whole issue gets discussed to death in this newsgroup, so I know the
drill forwards and backwards (as does anyone who reads posts here with any
regularity):
There is are the various "true" OEM versions of XP that come preloaded on
name-brand computers, and there is the "Retail OEM", aka "System Builder"
version of XP, that you can buy on a disk at any computer store for as
little as $90 USD.
How do they differ? The OEM you buy at the store is generic, direct from MS.
The "true" (preloaded) OEM versions are all different from the MS version in
various ways, having been reconfigured to the computer manufacturer's
hardware. This kind of OEM OS is tied to the exact build of computer it was
sold with.
So, going back to your post:
"What if he bought an OEM CD?"
If he bought a CD, it would have to be the generic MS OEM CD, the only kind
you can buy. As stated above, that CD would not work with a "true" OEM
Product Key. Based on this quote: "The original recovery CD's do not work",
you have to assume that the product key on the side of the computer is
"true" OEM, as the purchaseable version of XP does not come with recovery
CD's in place of of a regular XP disk..
This is all very deductive, and if you still see flaws in my reasoning, post
again. The situation could be more complicated than we know, and the OP may
not have told the entire story, such as where he got his computer, etc.