

We can't see your CD, if it was made (burned) by Dell you should be able to tell, if it looks like an Original XP CD, you don't need to worry about non of the above except the PID! You probably will see Dell's support info when viewing System properties, these could be altered or removed easily.

You have to check the files by yourself and see if Dell has added anything, If nLite editted these files, it most probably added to whatever Dell had already done (that's an IF), you can try and change the PID, then see if it works.
