My VPN connection does not work: Error 800
 

Most likely the security settings on your firewall or router does not allow you to establish VPN session. The simple solution is temporary disconnect your firewall. If you do not feel comfortable with this option, you have to read your firewall manual to go around this issue. Please Google for more help or visit this page at Microsoft.

My VPN connection does not work: Error 789
 

There are several types of VPN protocols. LT2P, PPTP, IPSec over TCP/IP, etc. We accept ONLY PPTP but your client tries to connect using LT2P. Please go to VPN connection properties or create the connection again and use the PPTP option. Please Google for more help or visit this page at Microsoft.

My VPN connection does not work: Error 733
 

You need to change your Settings. Our server accepts PPP Control Protocol and all other clients do not complain about this issue. Sometimes your VPN connection uses LP2P protocol (change it to use PPTP). Please Google for more help or visit this page at Microsoft.

My VPN connection does not work: Error 691
 

Maybe you entered a wrong username and password combination. It is also possible that after the payment your account was not created on the VPN server for some reasons. So, please contact customer support to verify this information and we are glad to assist you. The error may be related to your antivirus/firewall software, please see error 678 below.

My VPN connection does not work: Error 678
 

Make sure that port 1723 and IP Protocol 47 (GRE) are opened. You firewall may have closed these ports or your antivirus software may not allow to use these ports.

My VPN connection does not work: Error 619
 

Make sure that port 1723 and IP Protocol 47 (GRE) are opened. You firewall may have closed these ports or your antivirus software may not allow to use these ports. Try to connect your computer directly to the modem without router. Turn off your firewall if you have one. Check properties of your antivirus software to allow the traffic through these ports.

What are the system requirements for having VPN connection?
 

To install and run a VPN client, you may use any OS. Windows comes with a preinstalled VPN client.

The PPP link control protocol was terminated. Error 734
Many solutions advise the following:
Uncheck 'Include Windows domain' in the Options tab
Uncheck 'Negotiate multi-link for single link connections' in the Networking
- Settings tab
Uncheck 'Require data encryption' in Security tab
which have done without joy.
Another solution is to select 'Allow unsecured password' via the Security
tab - security options - validate my identity.
I only have two options available to me
'Require secure password' & 'Use smart card'
The allow unsecured password option is not available to me in the drop down
box.
Any feedback to reslove this issue would be welcomed so that I can use VPN.
Please Google for more help or visit this page at Microsoft.