Sticker WinXP key different from the one showing in Windows

Hey guys, i need you to clarify something to me here. I'm sorry if this has been discussed here before, but I did try search and found no clear answers.
Namely.... when i check my Windows XP key with a keyfinder, then it gives me a different one than the one marked on my windows sticker underneath my laptop. Why is that?
But the bigger question is, which serial should i use exactly when i need to reinstall my windows from the recovery disks or the partition?
Should i write down the one showing in Windows, or should i use the one on the sticker?
Thank you!

 

You won't be asked to input the key when you recover from the rescue disk or the rescue partition, but you will be asked if you try to install from an OEM windows xp cd. It is perfectly normal that your installation shows a different key than the sticker. All manufacturer use their VOL OEM license key to create a master windows installation which they will use to copy to all laptops they sell. Customising each laptop with their own personal key is very time consuming and unproductive.

 

and that volume license key is on the internet LOL

Looked up the first 5 characters on Google and bam there
it was

 

Oh, now i see! Thank you very much for that, Seb.