Most of the time, when you buy a computer from Dell, HP, Samsung, etc, Windows was installed using a volume key. That means it isn't the same as the key that's stuck to the computer. It also means that the volume key probably won't work on anything other than a Dell, HP, Samsung branded computer.
For example, I have a Dell laptop. It has a COA affixed to it with a Windows key. However, the key actually used by Dell does not match this key, because the key is actually a volume license key. Legally, Dell must affix a COA with a valid key, and that key can't be the same as a key on any other computer. If I choose to reinstall Windows and not do a system restore using the Dell DVD or restore partition, I can use the key affixed to my computer.
In your particular case, as long as you do a Samsung restore you will never be required to enter a key.