"You’d have surely co-related this to Windows Genuine
Advantage and you’ve got it right! Linux shall continue to
work and upgrade without bothering to know the origin of the
software. You may get it from some of the repositories or compile
it from source,there is no risk of losing functionality. Windows
Vista, on the other hand, relies on Windows Genuine Advantage
servers to verify the serial number of the product. If the servers
go down, as it did last year, Vista users worldwide are locked out
of their computers running legitimate copies of Windows Vista."