, GoddersUK wrote

It did get me thinking though - what would happen if Germany's supply of new Windows licences was cut off?

The US government would take retaliatory action against big German companies, that's what would happen. And that's why the ban hasn't taken place.

Microsoft were forced to send out a Windows Update disabling all Windows computers in Germany?

It wouldn't happen. Microsoft would refuse to do business in Germany before it took that kind of action.