Error 720:

[Slammer31p]

This worked on IBM A31p Windows XP SP2.  Thank you!

Norton 360 is culprit.  

WAN Minport (IP) - Symantec Network Security Miniport was added after steps completed.

Wasn't there initially. 

[zmiklovicz]

Hi Harrisb,

I did nearly all the steps, but I couldn't reinstall the PPTP and IP WAN Miniport devices, because the list of "Microsoft -> Network Adapters" didn't contained the devices (Step 3/1).

What can I do?

zmiklovicz

[elwoodblues]

After 8 months of wondering: "What's wrong with my Nokia E51?" - you made my day! Problems started after changing the ISP / mobile operator and I got already quite desperate as I thought that this was a hardware issue. I got a Huawei from operator, still believing that phone is the issue. Googled with "Error 720 Huawei" and there it was!

Guys at Lenovo: It's not so nice that ordinary people have to dig themselves into XP's or Vista's registrys, please prepare a nice patch for the problem!

Anyway - BIG thanks for the harrisb, you rock!

[Bob_Brown]

Thank you very much.  I have no clue how you figured this out, but it certainly helped me.

[hconslt]

I have T43 and the same error 720 occurrs when dialing up thru modem.

And found this information, but at step 1 RESOLUTION item 14 and 15 could not complete. Windows XP SP2 rejects due to the possible usage for computer booting (error message).

So regedit work was OK, but not complete Device Manager delete work on IP and PPTP.

I found Microsoft support page at article ID 810979 Rev 3.2 for the similar process but it is only for Windows 2000.

So Windows XP seems to show the different condition.

Hope I can get any information to resolve dial up on T43 win-xp.

[Coriolis]

Harrisb.

Thank you so much.  Solution worked pefectly for Lenovo X61 Tablet running XP pro with Rogers Mobile Internet  Using ZTE MF636 USB Modem. Modem installed would not connect (although it worked perfectly on a Dell laptop).

Symptoms in my case:  720 error was slightly different. "A connection to the remote computer could not be established.  You might need to change the network settings for this connection...".  As well, I did not have any yellow exclamation marks showing up on Wan miniport network adapters (and only one of each).  However simply refreshing the IP config using netsh was not effective on its own.  Had to do the whole procedure which was well documented and easy to follow.

Thanks again. Great post

[thundercleese]

Thanks, works great!

[GomJabbar]

Wow, I am impressed!  Great Guide!  It takes special knowledge to come up with such a solution!

My wife just bought a T-Mobile webConnect Jet USB cellular modem (Huawei UMG 1691) to replace an old Sony Ericsson GC-83 cellular modem for her T42 ThinkPad.  The new T-Mobile modem would not connect, giving the "Error 720" message.  T-Mobile data support did not know how to solve this problem.  I Googled around looking for a solution to this "Error 720" and came across this guide.  I was out of state on business but was able to talk my wife through the guide over the phone with SUCCESS!!!

Many Thanks!

[yrw]

Hello, everyone!

I'm from china, and my english is not very well. Thus, I can't understand harrisb's solution steps exactly when the same problem came to me. The key point is step2(3), viz where the semicolon is place. For example, it's like this "; Excludefromselect=\" or

";

Excludefromselect=\" with a blank line before. 

Are they different? Guys, please help me while you know this. Waiting on line,Thanks very much!

[yrw]

Or like this:

[ControlFlags]
;ExcludeFromSelect =\
    ;SW\{eeab7790-c514-11d1-b42b-00805fc1270e},\
   ; MS_IrdaMiniport,\
   ; MS_IrModemMiniport, \
   ;MS_L2tpMiniport,MS_PptpMiniport,MS_PtiMiniport,\
   ; MS_PppoeMiniport, \
   ; MS_NdisWanAtalk,\
    ;MS_NdisWanBh,\
    ;MS_NdisWanIp,\
    ;MS_NdisWanIpx,\
   ; MS_NdisWanNbfIn,MS_NdisWanNbfOut

Am i right?