Slipstream Win XP with nLite

When I purchased my Thinkpad from IBM, Win XP Home was not included on a CD, only on the HDD with a hidden partition for system recovery. Well, this is really stupid, and I'd like to do a full HD format for spring cleanings sake, but I cannot do it with IBM's setup. So I saw this article of "<A HREF="http://www.short-media.com/printcontent.php?print=r&id=284" target="_new">Slipstreaming</A>" Windows with nLite over at Short Media.

Great tutorial, and it even seems to want to work from the ci386 dircetory from my HDD, except that I'm missing a file called win51ic (no extension metioned), it tells me to copy this file off my XP disc into "c://". I have another copy of XP Home upgrade on CD, can I use the win51ic file on it (Istill need to look and see that it's there, but it's not with me right now), and if so where is "c://" anyway? Is that the ci386 directory?

Second question, as I already said, I have that Win XP upgrade on CD, and I slipstream using that, and still input the XP CD Key for my Thinkpad? Or would I have to use the one from the upgrade disc?