Best Portable External Hard Drives Reviews

Under normal circumstances, the operating system can recognize it as a “removable storage device” after the external hard disk connected with it, and automatically add drive letter in the “My Computer”. If the system identifies it as “Unknown USB Device”, then the external hard disk will not be able to use, when this happens, you may find out the reasons in the following order.

First, the settings problems associated with the system installation
1. Do not think that as long as the motherboard has USB interface, you can use removable hard disk, depends on whether the system supports. Windows2000, WindowsXP and above versions of the system can directly support external hard disk, and not need to install the driver to use, while in Windows98 to use external hard disk must be installed with the driver, or the system will be external hard disk identified as “unknown USB Device. ”
2. For some Windows98 users, the external hard disk installed the driver, you can see the external hard disk icon from the Device Manager, but the Explorer does not include the corresponding letter symbol, and this is the system set up properly result. In the Device Manager, double-click the Hard Drive icon, and click the pop-up window in the “Properties” button, and you could see the “disconnect”, “can delete”, “Sync data transfer” and “INT 13 unit” 4 options, which “can delete” a previous system default is no tick, and check this option, restart your computer, you can see the new external hard disk drive letter in the Explorer.

Second, the motherboard USB interface issues
As the motherboard USB port problems caused external hard disk is not working, mainly from the following address:
1.USB interface is not open: in some old machines (including some branded machines) Although there are external USB interface, but it is off by default in BIOS, so even if the system supports is not OK, it should check the BIOS settings USB interface option is open: When you start your computer holding down the Del key to enter BIOS settings, in the “Chipset Features Setup” or “Integrated Peripherals” will “OnChip USB” is set to “Enabled”, save and reboot the computer.
2. The system does not support the USB interface: This also was seen in some old computer. As the author of this platform compatible, motherboard is the flagship of the VISTA710V2, motherboard chipset, using a VIA Apollo MVP3, external USB interface card system could not recognize (the installed Windows Me and Windows 2000 dual-boot), in the “Device Management device “not found in” Universal Serial Bus controllers. ” Internet an investigation, the original problem is the motherboard chipset, and quickly downloaded from the Internet for the latest motherboard BIOS update, then downloaded the VIA chipset available exclusively for the USB driver patch, my computer finally recognized the “Removable Storage equipment. ”
3.USB interface, insufficient power supply: the vast majority of external hard disk work required to 5V Voltage, 0.5A current can be directly through the motherboard’s USB port supply, but some USB-powered board not reach this value, thus external hard disk can not be led to the system identification. Fortunately, a dedicated HDD enclosure USB connection line, a majority of separation of PS / 2 connectors, so long as the connector plug in the motherboard’s PS / 2 interface, it will be ok.

Third, improper operation led to the external hard disk can not be used
Due to improper operation caused by external hard disk is not working, mainly refers to the plug external hard disk is not the time to master.

1. Before docking external hard disk, you should shut down the running applications, and do not plug in the system startup process.

2. There will be a process to read and recognize external hard disk when it has just connected to the system, it is best not to carry out any operations before the end of this process (recommendations to divide less partition, sub-district the more, the system identification plate longer), you have to wait until external hard disk light stabilized.

3. The mobile hard drives will appear the situation that it can be used before, but occasionally can not be used, first delete “Unknown USB Device” in the “System Device”, and then unplug the external hard disk, and then reboot the system, and then connected it, the fault can be solved in general.

4, External hard disk its own problems

If the failure exclude the above reasons, the external hard disk still can not use, it is very likely to be external hard disk itself has a problem. Mobile hard drives are relatively simple structure, mainly by the disk drive casing and the composition of notebook computer hard drives, hard disk box is not easy in general bad, problems are mostly caused by laptop hard drive. External hard disk itself in order to avoid hardware damage, you should pay attention to the following aspects:

1. The use of external hard disk should be placed on a stable place, do not move and make it shaken when it read and write.

2. When you unplug and move the hard disk, you should in strict accordance with procedures: such as the hard disk does not read the disk, double-click the task bar bottom right corner of the “unplug or eject hardware” icon, first “stop” the use of equipment in the window that appears, and then remove the device from the system option, the last unplug the HDD from the computer (can not unplug the hard disk when it read and write, otherwise it’s easily damaged laptop hard drive).

3. Even in the non-work state, vibration is also the biggest killer of external hard disk, which requires users to take effective damping measures when carry out external hard disk (some brands of external hard disk is doing better, the equipment itself has taken the anti-shock measures), it is best put it in a box surrounded by plastic foam.