So, uninstall the device in Device Manager and reboot the computer. If it doesn't reintall all of the necessary drivers, install them from the media you got with the device (if any). Or go to the manufacturer's website and download the appropriate drivers for the device. Or in the properties page of the device, select the Driver tab and click on the Update Driver button and have the system search for more appropriate drivers for the device.
If you're asking for technical help, please be sure to include all your system info, including operating system, model number, and any other specifics related to the problem. Also please exercise your best judgment when posting in the forums--revealing personal information such as your e-mail address, telephone number, and address is not recommended.
a device is not working properly