Windows XP reformat dilemma!

Background info: A few years ago I bought my PC with an OEM version of windows xp home edition, it came with the disk and a product key, and since then I've reformated several times.

Here's my problem: I've lost my windows XP cd somewhere in the house and I couldn't find it, and the PC was really in dire need of a reformat. So I went to a torrent website, and found a windows XP home edition (although it had SP3 already, it was the only home edition I could find), and I downloaded it and burned it to a CD, fully intending to use the product key I had already purchased (ie, I'm not pirating).

Problem is, during the install, it said it wasn't a valid CD key. It let me continue without using one, but I've read up and the consensus is that I have 30 days to input a cdkey. Note, the torrent is a direct re-seed from, http://msdn.microsoft.com/en-gb/subscriptions/downloads/default.aspx and the only reason I downloaded it via torrent is because it's faster.

It's installing right now as I type this, but I just wanted to understand why it wouldn't accept my CD key. I'm not sure if it will or will not accept it once the OS is installed, and I'll update once I do, although my leading theory as to why it's not working is that it's either not an OEM install (not sure how it knows?) or that it already comes with SP3.

The SHA1 for my downloaded copy is 5A6B959AD24D15DC7EBD85E501B83D105D1B37C6

Perhaps a reason is because I took the "Windows XP Home with Service Pack 3 (x86) - CD (English)" file instead of:
Windows XP Home N with Service Pack 3 (x86) - CD (English)
Windows XP Home KN with Service Pack 3 (x86) - CD (English)
Windows XP Home K with Service Pack 3 (x86) - CD (English)

The main differences being the N, KN, or K, which I can't find any clarification on.

Edit: Never mind about the N and KN and K things, those just signify edited versions for Korean and European releases. (I'm in Canada)

 

bump i need help

 

Who made the computer? Chances are very high you're going to need an OEM disk from the manufacturer (IE: Dell, HP/Compaq, Gateway, Sony, etc), as XP Home/Professional OEM keys that came with hardware can't be activated with a non-manufacturer specific disk.

 

i did, but i had the shop assemble it. It wasnt a brand name, just pieces i picked out and put in the list.

i dont buy that its restricted, because when i bought the laptop im on now, it came with vista but i reformated and used the same XP that i had bought before.

 

one key per user per machine.

 

Where did you get your CD-key? From the bottom of your laptop or on the sticker on an XP pamphlet that came with the CD? Is it OEM key or retail?

The key on the bottom of your laptop frequently won't activate unless you have the actual OEM disk from the manufacturer where you got the PC. And in that case it will ONLY work on that specific machine, or brand of machines.

A generic OEM disc will work anywhere, except OEM will mean only activations are allowed on one machine ever. No transfer allowed. Although MS is somewhat lenient in that regards, if you call every few years to say your mobo or CPU died or something.