hey there

this link gives a number of troubleshooting steps to resolve this issue:

http://ghost301tech.wordpress.com/2009/10/29/error-651-in-windows-7-a-killer-for-internet-connectionvpn/

this also:

http://social.answers.microsoft.com/Forums/en-US/w7network/thread/9dad24b2-52fb-47c8-b65e-dac29b54cfd1

it seems that there is actually no formal fix, but if you look at the first link there are approx 10 different things to try to clear this error. I would work through them from the beginning and hopefully it'll clear the problem.

i would also suggest making a system restore point, in case you need to roll back to your previous working config.

see:

http://www.howtogeek.com/howto/3195/create-a-system-restore-point-in-windows-7/

good luck!

here it is:

Update (31.12.2009): It can easily see that there are a lot of Windows users have been bugged by this error (this post has occupied one third of the total visits of my blog), and I hope this article can help to solve your problem. But please be aware though, all the solutions were gathered from internet, such as article, forum etc., and I can’t guarantee that they will work for you. If they did, you are always welcomed to reply and let people know what have you done to solve your problem. Else, I am sorry that I couldn’t help you, perhaps you can ask for help from your ISP. I have updated several more possible solutions based on some readers’ replies.

You try to initiate the broadband dialer in Windows 7 and only found that it doesn’t work and returned with an error 651: Your modem (or other connecting device) has reported an error. And you had tried to restart your PC, your router, your modem etc. and the problem doesn’t go away. And eventually you want to bang your head to the wall because you can’t solve the problem, nor you can find solution online because you are not able to get online!

Same thing happened to me last few days which caused the update of the blog delayed. During some normal surfing, I found out that the connection was hang, thus I just disconnect the internet connection and try to reconnect. But hey, I can’t connect back anymore, with the error 651 while everything (hardware, Windows etc.) were ok. So for a few days, I can’t update my blog and I was trying to find solution for it in the office (don’t tell the boss, won’t ya?).

What I have found?

It is not hard to find the users that have the same problem as mine on the internet (you might want to praise internet a little bit?), but surprisingly this error seems bugged some Windows 7 (Beta or even RTM) users and it seems there is no official solution for it.

There is a lot of workarounds, suggested, of course, by other users since I mentioned there is no official fix for it. If you have this problem in Windows 7 (or may be Windows Vista/XP as some of the solutions works on them), check out what I have found:

1. Replace the raspppoe.sys in Windows/System32/Drivers directory. (High Risk!) source

Some of the user claimed that by replacing the raspppoe.sys in Windows 7 with the Vista one seems to be able to solve the problem. However, it’s a no for me. It doesn’t solve my problem as after replacement, it keep giving me error 797. And I myself doesn’t think that the error was caused by it because this method only works for those computers that equipped with Windows 7 and already have this error 651, which is not my case.

Quoted from Windows Reference.com:

The RAS PPPoE driver file “raspppoe.sys” found under c:\windows\system32\drivers folder seems to be the root cause of the problem. Fortunately, we can workaround the problem simply by renaming the original raspppoe.sys file to something like “raspppoe_orig.sys” copying a working file from a Windows Vista system. If you do not have access to a Windows Vista system. click here to download raspppoe.sys file (unzip).

I do not suggest for the replacement for the system file as it might cause even more problems if you doesn’t handle it well. However, if you insists of trying your luck, go ahead. If you having problem in replacing or renaming due to the error of TrustedInstaller thingy, check out this link. Take over the ownership of the file and replace it with the Vista one.

2. Uninstall Microsoft Virtual PC 2007

Over the replies in the windowsreference.com page, some users suggested that by uninstalling Microsoft Virtual PC 2007, the problem seems to be fixed. I uninstalled my Virtual PC which comes with Windows XP mode that exclusively for Windows 7, but it doesn’t solve the problem as well. If you have Microsoft Virtual PC 2007 installed, go ahead uninstall it and see if the problem go away from you.

3. Disable IPv6 for your connection source

I also found that some users claiming that by turning the IPv6 for your dialer, the problem can be solved. It is not in my case either.

4. Uninstall modem source

I am not sure which Windows it can be applied, but I supposed this is for dial up modem, but nevertheless, it still linked with error 651, and obviously, it can’t be applied in my problem since I am not using dial up modem.

5. Disable Windows Vista/7 auto-tuning feature source

One user suggest that the auto-tuning in Windows Vista/7 has broke down and he suggested a workaround to disable it prior to firmware upgrade for your router. This seems promising but yet, it doesn’t solve my problem either, as I am not using router.

6. Disable some special function of your LAN card source

The user over the Technet which have the same problem as mine has tried to turn off some special feature in LAN card such as Interrupt Moderation etc. and it seems able to solve the problem for temporary. But again, not for me.

7. Reinstall LAN/NIC card drivers

Most common suggestion by the community but still, it’s not the case for me. Both of my LAN card working well.

8. Reinstall networking in Windows Vista/7 source

Some says that by uninstalling the networking in Windows seems to make the problem go away. Again you know it doesn’t work for me.

9. Perform clean boot source

The moderator over Technet suggested to a user that having the same problem to perform clean boot to find the root of cause, and replace the raspppoe.sys file as well. Too, not working for me. None of the Windows/Non-Windows services caused the problem.

10. Uninstall Sun’s Virtual Box

One of the reply saying that it solved the problem by uninstalling Sun’s Virtual Box, along with Microsoft Virtual PC. I am not sure but perhaps there might be some conflict between the virtual network driver with the real one. You can give it a try if you had any virtualization software installed in your PC.

11. Recreate Dialer and restart the ADSL modem/router

This perhaps works if the error occurs when something hanged during the connection. Remove the dialer and create a new one, then restart your PC. Turn off the ADSL modem/router, wait for more than 30 seconds, then turn it on. Then try to connect.

12. Avoid sudden connection cutoff by software (preventive method)

This is from my own experience, I not sure how and why, but it just meant for sharing. One day, I had my connection up, and I install Norton Internet Security without disconnecting the broadband. As usual, a Internet Security Suite will have bunches of modules to protect your PC through networking security, so I did some necessary network scanning with it without turning my broadband off. Then all of the sudden, my broadband disconnected and when I try to reconnect, error 651 occurs again. Fortunately it doesn’t stay long as I managed to connect after waiting for a few minutes without doing anything, so I have learnt that when you know some software will going to cutoff your internet connection due to some reason, disconnect it first before proceeding.

Conclusion

With frustration of course, I ranged up my ISP (TMNet, Streamyx, Malaysia) for generating a technical report to solve the problem which I expect they will send me technicians to check for the problem as I suspected it is hardware problem (modem, LAN card etc.). But out of surprises, my connection is back without error 651 anymore. Then only I realized that it can be caused by my ISP side. I am yet to receive their call which I am going to enquire what happen to my broadband, but I am glad that the problem has solved.

So, if you had tried everything that I suggested, try to contact your ISP service centre, they might be able to solve for you. Good luck!

ok, this is the Windows Vista file though and not Windows 7, I don't know if you tried Vista or 7 file..