Mark, in lieu of obtaining Sony's install media CD, OP's scenario
*should* work:
1. Obtain *generic* OEM installation CD for *correct* type of XP (Home
or Pro).
2. Use it to install XP and use the Product Key found on the COA sticker
on the PC. Note that using the other Product Key (the so-called "golden
master" key which can be determined by using programs like Belarc
Advisor or Magical JellyBean Finder won't work.
So, to OP, you may not be able to use *any* OEM CD. For instance, using
another branded OEM installation CD (e.g., Dell) won't work because of
SLP (System Locked Pre-Activation). You will need to use a generic
(e.g., System Builder) OEM CD of the *correct* type of XP (Home or Pro).
And if you wish to use it to perform a repair install instead of a clean
install, the Service Pack levels must match. If they don't, you should
be able to create a new installation CD slipstreaming the Service Pack
so that the levels match.
Also to OP: Why do you believe you need to reinstall Windows in the
first place? What is the exact error message?