Microsoft UPDATE:  

9/13/2022: Appreciate your patience, it has been resolved with a server-side change. Voice typing (Win+H) should now open and function. Read more here....

The following windows error message may occur when trying to use the Windows dictate (Error Code 0x800704cf).

According to Microsoft posts on Sept 1, 2022 there is nothing wrong with your PC, this is currently a bug being reported by many people, it appears to be a server side issue, Microsoft is aware of this and will hopefully provide a patch soon.

The topic is being tracked here: in Microsoft Feedback