An anonymous reader shared this report from Neowin:
Offline Windows activation has been possible to do using the phone. However, it looks like Microsoft has quietly killed off that method as users online have found that they are no longer able to activate the OS using it... [As documented by Windows user Ben Kleinberg on his YouTube channel], Now when trying to activate the OS by attempting to call the phone number for Microsoft Product Activation, an automated voice response says the following: "Support for product activation has moved online. For the fastest and most convenient way to activate your product, please visit our online product activation portal at aka.ms/aoh"
If you are wondering, that link takes users to the Microsoft Product Activation Portal for online activation. Thus it appears that offline ways to activate Windows may no longer be available even though the official support documentation by the company may not reflect it yet.
Read more of this story at Slashdot.