In fact, here's the entire fix suggested for this problem.
RESOLUTION
To resolve this problem, reinstall SP1 for Windows XP.
WORKAROUND
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.
If you cannot reinstall SP1, verify that the Objectname string value is set to LocalSystem in the following registry subkey:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\RasMan
After you do so, delete the following registry subkeys. The presence of these subkeys on a Windows XP-based computer that does not have SP1installed can cause the symptoms described earlier:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\RasMan\PPP\EAP\25
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\RasMan\PPP\EAP\26
To delete these keys, follow these steps.
Note This procedure includes steps to make a backup of the registry keys before you modify them.
Click Start, and then click Run.
In the Open box, type regedit, and then click OK.
Locate and then click the following key in the registry:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\RasMan
On the File menu, click Export.
In the File Name box, type exported rasman key, and then click Save.
In the RasMan key, locate and then click the ObjectName string value.
If this value is not set to LocalSystem, follow these steps:
On the Edit menu, click Modify.
In the Value data box, type LocalSystem, and then click OK.
Locate and then double-click the following key in the registry:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\RasMan\PPP\EAP\25
On the Edit menu, click Delete.
Click Yes to confirm that you want to delete the selected registry key.
Repeat steps 7 to 9 to delete the following registry key:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\RasMan\PPP\EAP\26
Quit registry editor, and then restart your computer.