Important This article 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 Description of the Microsoft Windows Registry
When you try to install a serial modem or a universal serial bus (USB) modem on your Microsoft Windows XP Service Pack 2 (SP2)-based computer, you may receive the following error message:
Windows was unable to install the modem.
This problem occurs if there are no entries under the following Windows registry subkey:
Entry Name: Group Type: REG_SZ Value: Extended base
Entry Name: Start Type: REG_DWORD Value: 3
Entry Name: Tag Type: REG_DWORD Value: 4
Entry Name: Type Type: REG_DWORD Value: 1
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.
To add these entries to the subkey, follow these steps:
Click Start, click Run, type regedit, and then click OK.
Locate and then click the following registry subkey: