a GUID isn't an indicator, it's a fingerprint. so unless you want to draw a distinction between 'user' and 'machine' , yeah it is for identifying users. to be

a GUID isn't an indicator, it's a fingerprint. so unless you want to draw a distinction between 'user' and 'machine' , yeah it is for identifying users. to believe otherwise, especially with Microsoft involved, would be incredibly naive to their history.