In some countries, as for instance in my native Finland, computers sold with pre-installed Windows let you select the language at first boot, so called OoBE boot (
Out of Box Experience). This determines which language the user wants to set up his / her computer and in which language he wants Windows. In Finland for instance when you boot a PC first time, before it even asks your initial username, user is asked if he / she wants to use PC in one of the official languages of Finland (Finnish and Swedish), giving also an option to select English which in Scandinavian countries has an almost official "third domestic language" status.
This selection can not be changed later, i.e. if you later want to do a factory reset the language selection is no longer available, so it is extremely important to select the correct language at first boot. Most of my rigs are bought here in Germany but I have for instance an HP HDX16 laptop which when first booted asked if I want Finnish, Swedish or English. I selected English and can no longer go back to that selection so even if I decided to do a complete factory reset, this computer would be set up using English, without possibility to select the language again.
