Yukichigai

It consists of this:

I'm having similar problems. I used nLite to slipstream SP3 into a copy of XP Home OEM. Invariably, the image I make thinks it's a RETAIL version and asks me for the serial key on the label "on your Windows folder", rather than the one on my COA, and will not work with any valid COA key. I haven't tried slipstreaming without nLite to see if the issue is caused by MS's software or nLite, but regardless the issue is there. I'll attempt the fix suggested by konker and report back.