Windows 10 S to Windows 10 Switch Promotion

Microsoft has quietly extended a free upgrade offer that will allow some buyers of Windows 10 S to move to Windows 10 Pro.
MPSA and Select Plus Customers who purchase devices licensed with Windows 10 Pro in S Mode (Windows 10 S) with an Intel Core or AMD A8 or higher processor by March 31, 2018 may acquire a license to switch those devices to Windows 10 Pro for no additional charge.