Hardware Identify is a simple tool which can list the various devices on your PC.
This can be helpful if Device Manager is showing you "unknown" devices with no drivers installed. Normally, you won't be able to locate the drivers because you don't know which devices you have, but Hardware Identify should provide some clues.
Download, unzip and launch the program, and within a few seconds it displays a table listing all your hardware. Details include the device name, Manufacturer, error code (if there's currently a problem), class (USB, System, Port, Mouse and so on), driver version and Hardware IDs. Clicking any column header sorts the list by that field.
The table can be filtered in various ways. For example, click in the list box at the bottom left of the window, select "List hardware with no drivers installed" and click "Show Hardware" to see those devices.
If you still can't figure out what a particular device is, right-clicking it and selecting "Lookup Selected Device in Database" might help.
And there's also a right-click option to search Google for drivers, using either the device name or hardware ID (the cryptic USB\VID_8087&PID_8008&REV_0005|USB\VID_8087&PID_8008 - type string).
Note this is the portable version of Hardware Identity.
Hardware Identify isn't aimed at beginners, but if you're a knowledgeable PC user, trying to troubleshoot "unknown device" issues (after reinstalling Windows, say) then it may save you a little time.