Fix: PPTP VPN keeps on disconnecting after every minute

Scenario:

When you connect to your office network via VPN tunnel from an outside Windows 7 x64 workstation, VPN successfully connects and then automatically disconnects after a minute with various error codes as shown below:

Troubleshooting:

In the logs you’ll see events like below:

Event Type:     Information                                                 
Event Source:   RasMan                                                 
Event Category: None                                                 
Event ID:       20268                                                 
Date:           6/30/2011                                                 
Time:           9:28:33 PM                                                 
User:           N/A                                                 
Computer:       TESTPC1                                                 
Description:
using device VPN3-1 was disconnected.                                                    
                                                                    

Event Type:     Information                                                 
Event Source:   RasMan                                                 
Event Category: None                                                 
Event ID:       20267                                                 
Date:           6/30/2011                                                 
Time:           9:28:04 PM                                                 
User:           N/A                                                 
Computer:       TESTPC1                                                 
Description:
using the device VPN3-1.                                                    
                                                                    

Event Type:     Information
Event Source:   Microsoft-Windows-UserPnp
Event Category: None
Even
t ID:       20010
Date:           6/30/2011
Time:           7:15:38 AM
User:           NT AUTHORITYSYSTEM
Computer:       TESTPC1
Description:
The user connected to port true has been disconnected due to a system error. 
                                                                    

Event Type:     Information
Event Source:   Microsoft-Windows-UserPnp
Event Category: None
Event ID:       20010
Date:           6/30/2011
Time:           12:08:27 AM
User:           NT AUTHORITYSYSTEM
Computer:       TESTPC1
Description:
The user connected to port false has been disconnected due to a system error. 

Environment: The most probable case that you’ll be running a standalone install of an Antivirus software on that PC.

Cause and Fix:

In my case, the cause was the standalone install of Symantec Endpoint Protection client version 11.0.62000.754. 

The fix is to stop “Symantec Management Client” (SmcService) service and then VPN to my work network. 

Note: You can still have the actual Antivisu scanning service “Symantec Endpoint Protection” (Symantec AntiVirus, "C:Program Files (x86)SymantecSymantec Endpoint ProtectionRtvscan.exe") Running