If you want to establish a PPTP connection with a 40- or 56-bit MPPE using Windows 7 or above, you must configure the AllowPPTPWeakCrypto registry key. Using PPTP with MPPE on Windows 7 and Above It is highly recommended that you switch away from PPTP.
Use a standard-compliant PPTP client, such as the native Windows VPN client. Barracuda CloudGen Firewall supports PPTP VPNs with 40-, 56-, and 128-bit MPPE.
