If you are getting Error 720 when you try to connect to Sprint’s 3g network on a Sierra Aircard 250U USB modem, then don’t worry- here’s how to fix it.
Problem: When you click connect in Sprint’s utility you get Error 720.
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.”
Fix: (Thanks to harrisb on Lenovo’s forums: source)
Step 1: Uninstall the WAN Miniport (IP) and WAN Miniport (PPTP)
You’ll have to modify the registry in this step so make sure you back it up. (To restore, double click your exported file) – More info about the registry
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.”
Use regedit at your own risk (if you mess up, you may need to reinstall windows!)
6. Locate the following registry subkey:
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 [but do not do so now]
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 original copy of netrasa.inf and place a semicolon
in front of the line that starts "Excludefromselect=\" and
and continue with all following lines and then end with
"MS_NdisWanNbfIn,MS_NdisWanNbfOut" under the [ControlFlags]
section. (all lines between)”
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.
5. Delete the modified netrasa.inf and rename the original (which was saved as netrasa.inf.save) back to netrasa.inf
That’s it. Worked perfectly on my T60. Hope this helps, visit the source for more detail.