Activation Key for XP

Being mostly a Mac person, I’m used to tinkering with operating system “innards”, so in the course of trying to find a way to get the machine to read an ISO disk image as a “run disk”, I mistakenly re-named a drive on my old HP mini (Win XP), unaware that this would start the countdown on a de-activation time bomb... Apparently this qualifies somehow as a “significant hardware alteration”?  Not sure how that makes sense, as there’s nothing I’ve physically done to the laptop.  ANYhow, I now have two days to re-activate Windows, but as this laptop was a giveaway from an old employer, I don’t have any original Windows key to enter.  And of course, since this model has no optical drive, there never were any disks, to begin with, so...  my questions for the forum:

A) How does re-naming a drive (i.e. giving it a new letter using Administrative Tools) constitute a hardware change?  No hardware has been touched since it left the factory.

B) Is it even possible to GET an XP activation key?  Although I can get this old machine online (albeit only by using Google Chrome; IE doesn’t work), I cannot seem to connect to any servers via the control panels, activation wizards, and what have you... must be the dreaded MS “clock issue”... either that, or said servers no longer exist.  

C) Yes, I could purchase a new piece of hardware with Windows 12, or whatever the hell number it is these days.  But my question is about XP, and getting THIS machine to work again.  Other than this totally arbitrary demand for a re-activation (read: arbitrary demand for money), there’s really nothing wrong with it.  Boots up almost as quick as my MacBook Pro, and handles all appropriate tasks with the efficiency that XP was famous for.