Ok you guru's out there, I have the challenge of the year for you!! jaja, not really, but please read on.
I never really noticed it until today, but I installed some months ago Windows Vista Ultimate on a HP NC6000 computer. It installed ok and for the most part it has worked without major issues. I didn't use it very much as I had my work laptop and I used it for the most part for getting used to the new OS.
Now the laptop has undergone heavier use, and I installed a cool CPU Usage gadget in the side bar, and to my surprise, the second core is not in use!

I can't really tell if this has always been the case, but I think it has.
Now, before you send me to re-install the darn thing, is there a way to make this one multi processor? In Windows XP it is quite simple: Replace the uniprocessor versions of hall.dll, ntoskrnl.exe, an some other I don't remember right now for the multiprocessor versions and that was the end of it. Could it be that simple for Vista? I checked out the properties of hal.dll but the Details tab doesn't show the original filename, so I couldn't really tell if the file was for uni or multiprocessor machines.
If you guys are going to tell me that I need to reinstall, could you tell me what is it that I need to do to re-activate Windows? Do I need to call Microsoft?
Anyway, I talk a lot to make me feel important.

I'll shut up now.
Thanks!