Troubleshooting of Windows xp usb interface faults

generally, there are 3 to 8 USB interfaces on the current computer. But for some reason, some of these USB interfaces are normal, but some are faulty. Some can be used in a certain period of time, but sometimes it cannot be used. In short, USB interfaces often encounter various problems, which causes external devices to be unable to connect and use normally. In fact, the USB interface failure can be attributed to "hardware" and "software". The hardware mainly refers to whether the computer hardware is damaged, software refers to the failure of the USB interface due to an error in the Program settings of the computer. This article mainly analyzes the problem of USB interface faults in computer software, hoping to help you.
1. USB power-saving mode
In fact, the USB power-saving mode is enabled for Windows XP by default. This mode reflects the concept of green and environmentally friendly power-saving, however, some USB interfaces may be insufficient in power supply, causing intermittent failure of USB devices. Most of the reasons for the sudden failure of USB during the use of computers are due to power-saving mode. In fact, you only need to disable the power-saving mode and the USB device can be restored to normal.
method: Click the Start Menu. Open and run, and type "devmgmt. MSC "press enter to open the Device Manager, double-click" Universal Serial Bus Controller ", then you will find multiple" USB root hub ", double-click any one, open the "USB root hub properties" dialog box, switch to the "power management" tab, remove the check box before "allow the computer to close this device to save power", and click "OK" to return, after modifying the properties of each USB root hub, restart the computer so that the USB device can run normally.

2. unrecognized USB
There are many causes that cannot be identified by USB, including software and hardware problems, and perhaps the cause of the built-in driver of the system. Removable storage devices are more common in public scenarios, for example, USB cannot be identified when connected to Internet cafes. For whatever reason, the damaged registry can be fixed to solve the problem that USB cannot be identified. The method is as follows:
Step 1: Click the Start Menu. Open Run, type "cmd" and press enter to start the Command Prompt window, run the following two Commands: "Reg Add" HKEY_LOCAL_MACHINE \ SYSTEM \ CurrentControlSet \ Control \ Session Manager \ environment "/V" devmgr_show_details "/D 1/T REG_SZ/F" to copy the command and press Enter. and then execute the next command.
"Reg Add" HKEY_LOCAL_MACHINE \ SYSTEM \ CurrentControlSet \ Control \ Session Manager \ environment "/V" devmgr_show_nonpresent_devices "/D 1/T REG_SZ/F ". Then restart the computer.
Step 2: Click the Start Menu. Open and run, and type "devmgmt. MSC press enter to open the Device Manager, open the Device Manager, and click View on the menu bar. In the View bar, select Show Hidden devices. A check box appears to indicate that the device manager has been selected. In the Device Manager, find and double-click the "Universal Serial Bus Controller" project to unmount all the gray projects and USB large-capacity storage devices below, next, right-click the general serial bus controller project, select scan and check hardware changes from the drop-down menu, and unplug the USB device, this will solve the problem that USB cannot be identified.