The first time you connect a device that plugs into a universal serial bus (USB) port, Windows automatically installs a driver for that device. After a driver is installed, you can disconnect and reconnect the device without performing any additional steps.

Before you install your device

Check the instructions included with the device to determine whether a driver should be installed before you connect the device. Typically, Windows detects a new device after you connect it, and then installs the driver automatically. However, some devices require you to install the driver before plugging the device in.

Also, while most devices that have power switches should be turned on before you connect them, others require that you turn them on during the installation process. Because of issues like this, it's a good idea to read the instructions included with a new device before you connect it.

If the instructions that came with your device contradict the information in this topic, follow the instructions that came with the device.

Plugging your device in

If your USB device uses a power cord, you should connect the device to a power source and turn it on before connecting it.

Next, determine which USB port you want to connect your device to. If your computer has USB ports on the front, consider using one of those if you plan to frequently connect and disconnect the device.

Illustration of a typical USB cable and port
A typical USB cable and port

Plug the device into the USB port. If Windows is able to install a device driver automatically, you'll be notified that the device is ready to use. Otherwise, Windows will prompt you to insert a disc containing the driver for the device.

After installation is complete, check the information for your device to see if any additional software that might have been included with the device should be installed.

Occasionally you might have a USB device that Windows cannot recognize and that did not come with a disc containing a driver. If this is the case, you can try to find a driver for the device yourself. Start by checking the website of the device manufacturer. You can often download drivers from the support section of such sites. For more information, see Tips for solving problems with USB devices.


  • When connecting a device to a USB port on a USB hub, monitor, or other device that's plugged into your computer, ensure that the USB port has enough power to support your device. Smaller devices, such as USB flash drives and mice, and devices with their own power cords, such as printers, typically work properly when connected to an unpowered USB hub. Some devices that use more power, such as USB-powered scanners and web cameras, require a hub that has its own power cord to function properly. If a device doesn't work properly when connected to a hub, try connecting it directly to one of your computer's USB ports.

  • Devices that transfer large amounts of information, such as external hard disks, scanners, and video cameras, function best when connected to high-speed USB 2.0 ports. Some older computers may include only USB 1.x ports, or a mix of USB 1.x and 2.0 ports. If your device requires a high-speed port to function properly, check information provided by the manufacturer for your computer to ensure that the port you're using supports USB 2.0. If your computer includes only USB 1.x ports, you can add USB 2.0 ports by installing a USB 2.0 card inside your computer.

Connecting and disconnecting devices

Most USB devices can be removed and unplugged at will. When unplugging storage devices, such as USB flash drives, you should be sure that the computer has finished saving any information to the device before removing it. If the device has an activity light, wait for a few seconds after the light has finished flashing before unplugging it.

If you see the Safely Remove Hardware icon in the notification area at the far right of the taskbar, you can use this to ensure that devices have finished all operations in progress and are ready to remove. Click the icon and you'll see a list of devices. Click the device you want to remove.

You can use any USB port when plugging in a device that you've previously installed. However, the first time you plug a device into a particular port, Windows will install the driver for that device again.