Error 720: A connection to the remote computer...

[CraigK]

The solution I used to solve this is basically one developed by
"nortel", but I put all the steps together in one place to make it
easier for others. Here's the procedure:

Instructions (for WinXP) to fix: 
Error 720: A connection to the remote computer could not 
be established.  You might need to change the network settings 
for this connection.

Note that a key sympton of this problem is that the modem
connects and then disconnects just after trying to register
the computer on the remote network. 

These instructions were compiled from a couple of sources:

http://www.tek-tips.com/viewthread.cfm?qid=1225579

and

http://support.microsoft.com/default.aspx?scid=kb;en-us;810979.

Note that you can't uninstall TCP/IP in XP, which is why I
wrote up this version, but the procedure is basically the same.

Step 1:  Uninstall the WAN Miniport (IP) and WAN Miniport (pptp)

MPORTANT: This procedure contains information about modifying the registry. 
Before you modify the registry, make sure to back it up and make sure that 
you understand how to restore the registry if a problem occurs. For 
information 
about how to back up, restore, and edit the registry, click the following 
article 
number to view the article in the Microsoft Knowledge Base: 256986 
(http://support.microsoft.com/kb/256986/EN-US/) Description of the Microsoft 
Windows Registry

SYMPTOMS
When you try to use a dial-up connection to connect to your Internet Service 
Provider (ISP), you may receive the following error message during the 
"Registering your computer on the network" portion of the connection 
agreement:
Error 720 - the connection attempt failed because your computer and the 
remote computer could not agree on PPP control protocol.
Additionally, when you view the devices in Device Manager, you may notice a 
yellow exclamation mark (!) over the icon for the WAN Miniport IP (#2) device.
Back to the top	Back to the top

CAUSE
This issue may occur if the TCP/IP protocol has become unbound from the 
dial-up adapter, or if a conflict is created when a second WAN Miniport IP 
device driver loads.
Back to the top	Back to the top

RESOLUTION
To resolve this issue, uninstall the  WAN Miniport IP and PPTP devices. 
To do so, follow these steps:

1.	Right-click My Computer, and then click Properties.

2.	Click the Hardware tab, and then click Device Manager.

3.	On the View menu, click Show hidden devices.

4.	Under Network adapters, you will see WAN Miniport IP 
        devices. If a WAN Miniport IP device is listed, continue to the 
        following step. If no WAN Miniport IP device is listed, go directly 
        to step 16.

5.	Click Start, click Run, type regedit in the Open box, and then click OK.

WARNING: If you use Registry Editor incorrectly, you may cause serious 
problems that may require you to reinstall your operating system. Microsoft 
cannot guarantee that you can solve problems that result from using Registry 
Editor incorrectly. Use Registry Editor at your own risk.

6.	Locate the following registry subkey:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E972-E325-11CE-BFC1-08002BE10318}

7.	On the Registry menu, click Export Registry File, type backup-key in 
the File name box, and then click Save.

Note You can restore the changes that you make to this registry key. To do 
so, double-click the backup-key.reg file that you saved.

8.	Click each of the registry subkeys under this key, and then view the Data 
        column of the DriverDesc value to determine which of the subkeys 
        corresponds to WAN Miniport (IP). For example, the 0005 subkey.

9.	Right-click the subkey whose DriverDesc value data is WAN Miniport (IP) or
	WAN Minport (PPTP); (for example, right-click 0005), and then click 
	Delete. Click Yes to confirm that you want to delete the key.

10.	Quit Registry Editor.

11.	Right-click My Computer, and then click Properties.

12.	Click the Hardware tab, and then click Device Manager.

13.	On the View menu, click Show hidden devices.

14.	Under Network adapters, right-click WAN Miniport (IP) and then click 
Uninstall. Click OK to confirm that you want to remove this device.

15. 	Repeat for the WAN Miniport (PPTP).


Step 2: Reinstall the WAN Miniports

1. 	Find netrasa.inf in c:\windows\inf

2.      Make a copy of the file and name it netrasa.inf.save

3.     	Open the orignal copy of netrasa.inf and place a semicolon 
	in front of the line that starts "Excludefromselect=\" and 
	and continue with all follwing lines and then end with 
	"MS_NdisWanNbfIn,MS_NdisWanNbfOut" under the [ControlFlags] 
	section. (all lines between)

Step 3: 
     
1. 	Start a Add new hardware session (from Control Panel) and choose 
	that the hardware is already installed.  Choose to "Add New Hardware" 
	and then select "Network Adapters" followed by "Microsoft" and then 
	both the PPTP and the IP Wan miniport one at a time.  
	(NO need to reboot between these steps)

2. 	After you finish both then reboot.

3.      Select Start -> Run  and type:  netsh int ip reset c:\resetlog.txt

	(For details, see http://support.microsoft.com/kb/299357)

4.	Reboot and try your connection.


This worked for me and has worked for others.

Note that if you don't want to uninstall the two WAN Miniport devices,
you can disable them in the Hardware Manager and then proceed with
the reinstall as described above. This has the advantage of being more
easily reversible. 





"CraigK" wrote:

> I have a XP pro laptop with which I somtimes connect to the internet
> via a dialup modem when traveling. Using TWO different modems
> (one externa, one internal), I get the same error when I try to connect
> via dialup (boh wireless and ethernet work fine):
> 
> Error 720: A connection to the remote computer could not be established.  
> You might need to change the network settings for this connection.
> 
> This occurs after password and username have been verified and
> the modem reports that it is:
> 
> Registering your computer on the network...
> 
> It should NOT be registering the computer - I am not running
> a VPN. My sense is that somehow the OS thinks it sould be
> setting up a VPN when it should bot be doing so.
> 
> The dialup access works fine on any other desktop or laptop  I am
> certain this is an issue of something having changed in the registry
> so that dialup modem connections are damaged.
> 
> I have reset ip (since I cannot uninstall in XP pro).  I  I have updated all 
> service packs from Microsoft.  I have the e latest drivers and have rmoved and
> re-installed tehm.   I have run xp tcp/ip repair utility.  I have looked in 
> the event log of both the server and the laptop - nothing appears.  I am 
> running tcpip and client for Microsoft networks and have made sure they are 
> checked in the connection properties.  
> 
> I have found one solution on the web that involves uninstalling the
> MiniWAN devices, fiddling with an inf file, and then reinstalling. This 
> seems a bit awkward as a fix and before I try it, I wanted to see if anyone
> might have something a bit more direct.  Any help would be 
> greatly appreciated.