. "Microsoft uses PPTP for its VPN. Supposedly, at least. Microsoft has been known for claiming to use a protocol and then not be compatible with it at all, see e.g. Active Directory or Internet Explorer."@en . . . . "Microsoft uses PPTP for its VPN. Supposedly, at least. Microsoft has been known for claiming to use a protocol and then not be compatible with it at all, see e.g. Active Directory or Internet Explorer."@en . "Microsoft VPN"@en .