Download this app, its very good.
http://www.zhangduo.com/udi.html
Info in link.
neat little program.
Interesting - thanks
Unknown Device Identifier enables you to identify the yellow question mark labeled Unknown Devices in Device Manager. And reports you a detailed summary for the manufacturer name, OEM name, device type, device model and even the exact name of the unknown devices. With the collected information, you might contact your hardware manufacturer for support or search the Internet for the corresponding driver with a simple click.