You attach a USB-based device to a computer that is running Windows XP. Then, you try to scan for hardware devices. However, the computer may not detect the attached device, and you may not see the device in the My Computer folder.

You may experience this problem when you are using one or more of the following devices:

•	USB thumb drive
•	Apple iPod
•	External hard disk drive

Additionally, you may not see the iPod in the iTunes application.

Back to the top

This problem may occur if there are corrupted or incorrect keys in the registry.

Note There may be other reasons that a USB device is not detected. For related Microsoft Knowledge Base articles, see the "Similar problems and solutions" section.

Back to the top

Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base: To resolve this problem, delete the UpperFilters registry value and the LowerFilters registry value. These values may cause access problems. To do this, follow these steps:

1.	Click Start, click Run, type regedit , and then click OK.
2.	Locate and then click the UpperFilters registry value. This value is located in the following registry subkey: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E980-E325-11CE-BFC1-08002BE10318}
3.	On the Edit menu, click Delete, and then click OK. Note If you receive an error when you try to delete the registry subkey, you may not have correct permissions to edit the subkey. For more information about how to set or to change registry editing permissions, click the following article number to view the article in the Microsoft Knowledge Base: 310426 (http://support.microsoft.com/kb/310426/) How to set or change registry editing permissions in Windows XP or in Windows Server 2003
4.	Locate and then click the LowerFilters registry value. This value is located in the following registry subkey: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E967-E325-11CE-BFC1-08002BE10318}
5.	On the Edit menu, click Delete, and then click OK. Note If you receive an error when you try to delete the registry subkey, you may not have correct permissions to edit the subkey. For more information about how to set or to change registry editing permissions, click the following article number to view the article in the Microsoft Knowledge Base: 310426 (http://support.microsoft.com/kb/310426/) How to set or change registry editing permissions in Windows XP or in Windows Server 2003
6.	Exit Registry Editor.
7.	Restart the computer.

For information about how to contact Apple Computer, Inc., click the appropriate article number in the following list to view the article in the Microsoft Knowledge Base: Microsoft provides third-party contact information to help you find technical support. This contact information may change without notice. Microsoft does not guarantee the accuracy of this third-party contact information.

Back to the top

For more information about USB devices that are not detected, click the following article number to view the article in the Microsoft Knowledge Base: For more information about the error message "The camera device is not correctly recognized", click the following article number to view the article in the Microsoft Knowledge Base: For more information about USB mouse devices that are not detected, click the following article number to view the article in the Microsoft Knowledge Base: For more information about how to troubleshoot unknown devices, click the following article number to view the article in the Microsoft Knowledge Base: For more information about the error message "USB device not recognized", click the following article number to view the article in the Microsoft Knowledge Base: For more information about reconnected USB devices that are not detected, click the following article number to view the article in the Microsoft Knowledge Base: For more information about missing devices, click the following article numbers to view the articles in the Microsoft Knowledge Base:

Back to the top

The third-party products that this article discusses are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, about the performance or reliability of these products.

Back to the top