Microsoft KB Archive/811235

Knowledge Base

Nokia cellular telephones do not work correctly with a Bluetooth transceiver

Article ID: 811235

Article Last Modified on 3/7/2007

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APPLIES TO

• Microsoft Optical Desktop Elite for Bluetooth
• Microsoft Wireless Entertainment Desktop 7000
• Microsoft Wireless Optical Desktop for Bluetooth

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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

SYMPTOMS

When you try to use a Nokia cellular telephone with a Bluetooth transceiver, the telephone may not work properly. This issue is not limited to Nokia phones. For example, the Sony au c413s and the Docomo (Sharp) PALDIO 633 may have the same issue and therefore require the resolution that is described later in this article.

CAUSE

The link key exchange is susceptible to "sniffing" (the process of viewing line or connection data by using a sniffing tool or program). If the initial link key exchange is captured, any future connections could be listened to by an outside Bluetooth device.

To minimize that risk, devices that a connection will be established to are instructed that link keys will change for every new connection. Some radio manufacturers and vendors misunderstood the specification and changed it so that this change occurred immediately. Because of this immediate change, they disconnected, losing the state of the link key exchange, and therefore not working with the Bluetooth stack.

If you use this workaround, be aware that it reduces your security for all bonded connections. However, anyone sniffing your connection must be within approximately 30 feet on a low-power radio, and would have to sniff your first bonding process.

RESOLUTION

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 resolve this issue, add the missing registry value. To do this, follow these steps:

1. Start Registry Editor. To do this in Windows Vista, click Start, type regedit in the Start Search box, and then press ENTER.
   
   If you are prompted for an administrator password or for a confirmation, type the password, or click Continue.
   
   To start Registry Editor in Windows XP, click Start, click Run, type regedit, and then click OK.
2. In Registry Editor, locate the following registry key (where bus_type is the bus type that is being used by your Bluetooth device (for example, PCI, PCMCIA, or USB): '

   HKEY_LOCAL_MACHINE\System\CurrentControlSet\Enum\bus_type

3. Expand each subkey in the bus_typekey to locate the Device Parameters' key, which contains the Bluetooth identification number. For example, the key for a device USB might be located in the following key: '

   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\USB\Vid_0c10&Pid_0000\120000AB0AFC\Device Parameters

4. In the right pane, right-click a blank area, point to New, and then click DWord.
5. In the Name box, type Change Link Key Always.
6. In the right pane, right-click Change Link Key Always, and then click Modify.
7. In the Value box, type 0.
8. Quit Registry Editor.
9. Unplug and reinsert your Bluetooth Device for this change to take affect. If your Bluetooth device is embedded, then restart your computer for this change to take affect.
10. Run the Bluetooth Authentication Wizard to re-authenticate the device.

MORE INFORMATION

The third-party products that are discussed in this article are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, regarding the performance or reliability of these products. To learn more about editing the registry in Windows Vista, follow the instructions in the "Registry management strategies for IT Pros" topic in Windows Vista Help and Support. To view the topic, follow these steps:

1. Click Start , and then click Help and Support.
2. In the Search Help box, type Registry management strategies for IT Pros, and then click Search Help.
3. Click the appropriate topic.

Keywords: kbinfo KB811235

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