In Search Of 'Mystery' Devices
I use another method to figure out the "mystery" yellow-question mark hardware in Device Manager. You need to go into the Registry and navigate to HKLM\System\CurrentControl\Enum\PCI
This is where Windows tracks all of the hardware it detects (i.e. enumerates). Each key in this hive will list the Vendor ID and Device ID for every piece of detected hardware. The IDs are 4 digit hexadecimal numbers.
Example Key: VEN_10DE&DEV_0028&SUBSYS_006010DE&REV_15
Vendor ID is 10DE
Device ID is 0028
Under each key there are values listed. Look for the DeviceDesc value to get a plain language description of the hardware device (e.g. "NVidia Riva TNT Pro" for the key listed above). If you see a device description that says "Unknown", that's your yellow question mark item.
Make a note of the Vendor ID and Device ID and cruise on over to http://www.pcidatabase.com
. Enter the IDs to get a clue about the manufacturer and model of the device. Hopefully you will be able to download drivers from the vendor's website.