Windows 7 , PPTP VPN error 807 and 800

Dear Experts

Please don't steer the topic from PPTP to IPsec and other types of VPN which is more secure than PPTP,,,,etc

I have got this scenario windows 7 is acting as vpn client at home and windows XP is acting as vpn server at work.

At home (LAN address is 192.168.[B]10[/B].x/24)And I configured windows 7 as VPN client same as here :

http://www.hideipvpn.com/2009/09/h [...] -tutorial/


At work (LAN address is 192.168.[B]1[/B].x/24) I configured XP SP3 as VPN server same as here (except I could not enable PPTP Passthrough on my router because I could not find that option) :

http://www.home-network-help.com/pptp-vpn-server.html

Please be aware
On the vpn server, I have selected administrator as username to be allowed for vpn, subnet that vpn server is using, is : 192.168.1.70-73

On the vpn client I am using the correct username/password.

Security I tried below combinations with no joy:

Type of VPN : Automatic,,,,,,[B]error 800[/B]
Data encryption: Optional encryption (connect even if no encryption)

Type of VPN: Point to Point Tunneling Protocol (PPTP),,,,,[B]error 807[/B]
Data encryption: Optional encryption (connect even if no encryption)


Router that I am using at work (where XP is connected to it) is :

2wire router with below details :

IModel: 2701HGV-W Gateway
Hardware Version: 2701-100655-004
Software Version: 5.29.113.16

Port forwarding 1723 was enabled

Whenever I try to establish a vpn tunnel I am receiving either error 807 or 800

Note:
The VPN server (work deskto) was working when I had at home VPN client as an XP OS not windows 7, but when I upgraded from XP to windows 7 I lost my vpn connection.


Thanks

Now I have got couple of question :

1- Do I need to enable GRE Protocol 47 (PPTP Pass Through or VPN Pass Through) as well, when I read couple of online threads they suggested to enable VPN Pass Through (GRE Protocol 47) with some nasty routers

http://www.chicagotech.net/vpnsetup.htm

2- I had not enabled GRE Protocol 47 (PPTP Pass Through or VPN Pass Through)when I had XP as client before upgrading to windows 7

3- If option 1 is not necessary what could cause this problem ?

Are you saying my work router and home router should be configured for GRE 47 ?

Although I was about to try that but I could not find that option on my work's router !!! but confusing me why didn't I need to configure that to my work router when I used to have windows XP at home acting as vpn client before upgrading to windows 7 and VPN was working!!!

I will try that

Noted

Credits goes to other forum

udp port 500 is not necessary to be configured

The problem was with Norton 360 V5 firewall when I disabled it, VPN worked

As you have mentioned GRE 47 should be enabled on both routers home's router and work's router and I did the test below :

1- On home's router cable router (simple cisco provided by my ISP) 'PPTP pass through' is enabled,,,I guess not sure the work's router 2wire has 'PPTP pass through' or GRE 47 enabled by default, and firewall (Norton 360 V5) on the VPN server (Desktop computer at work) is disabled,,,,,,VPN worked

2- On home's router cable router (simple cisco provided by my ISP) 'PPTP pass through' is disabled,,,I guess not sure the work's router 2wire has 'PPTP pass through' or GRE 47 enabled by default, and firewall (Norton 360 V5) on the VPN server (Desktop computer at work) is disabled,,,,,,VPN didn't worked


Please see the snapshot below:

http://i54.tinypic.com/2s8nsrp.png