Microsoft has soo much advertising power with Windows 10, they can now put banners up in Windows Explorer via updates. You may see one such as this:
'Save your documents and photos to OneDrive'
The setting is called Show Sync Provider Notifications however it has been used for other purposes such as when you do a feature update
To prevent this from happening push out a group policy User preference
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
Value: ShowSyncProviderNotifications
Value Type: REG_DWORD
Value Data: 00000000
Base: Hex
