This problem occurs when no device is connected to a USB port. That makes the USB driver set the Open Host Controller Interface (OHCI) controller to a suspended state. When the OHCI controller is in a suspended state, it cannot always detect when you add a new USB device to your computer.
To fix this problem on a Windows XP-based computer, you must be running Service Pack 1 (SP1) or later. To determine if you have Windows XP SP1 or later, click Start, click Run, type winver, and then click OK. If SP1 or later is not listed in the About Windows dialog box, then use Windows Update to install the latest service pack before you try to fix this problem.
Steps to fix this problem
Create a new registry value that prevents an OHCI controller from entering a suspended state.
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:
322756 How to back up and restore the registry in Windows
To create a new registry entry that will disable the Selective Suspend feature of the USB hub driver, follow these steps:
Click Start, click Run, type regedit, and then click OK.
Locate and then click the following key in the registry:
On the Edit menu, point to New, and then click DWORD.
Type DisableSelectiveSuspend, and then press ENTER.
On the Edit menu, click Modify.
Type 1, and then click OK.
Note This setting affects all USB host controller drivers in the system.
If the value of the DisableSelectiveSuspend registry entry is set to 1, the Selective Suspend feature is disabled. Additionally, the Allow the computer to turn off this device to save power check box does not appear on the Power Management tab for the USB Root Hub.
Did this fix the problem?
To verify that the automatic fix worked, restart your computer. If the computer now recognizes the USB device, the problem is fixed, and you are finished with this article.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section. This problem was first corrected in Windows XP Service Pack 1.
For more information about USB problems in Windows XP or Windows Server 2003, click the following article numbers to view the articles in the Microsoft Knowledge Base:
310575 Advanced troubleshooting tips for general USB problems in Windows XP
925196 A computer that is running Windows XP cannot detect a USB thumb drive, an Apple iPod, or an external hard disk drive
810090 Universal serial bus devices may not always be detected when you start or resume the computer in Windows 2000 or in Windows XP
892050 A USB device that is connected to a USB 2.0 hub is not detected in Windows XP Service Pack 2, Windows Server 2003 Service Pack 1, or Windows Server 2003 x64 versions
If these articles do not help you resolve the problem, or if you experience symptoms that differ from those that are described in this article, search the Microsoft Knowledge Base for more information. To search the Microsoft Knowledge Base, visit the following Microsoft Web site: