Same as the 2 previous questions I've posted:
Most of the questions tagged with microsoft (180 questions) relate to Microsoft products (mostly Windows and Office) and they are not questions about Microsoft corporation or Microsoft products in general, and that's why I don't think they should be tagged with microsoft.
Microsoft tag wiki:
Microsoft is a software company best known for their Windows line of operating systems.
[microsoft]
,[google]
and[mozilla]
and all the ones you mentioned in the 'useless' category.