Device Manager helps you determine which hardware devices are installed on your computer, and whether or not they are working properly. If one of your devices is not working properly, an error icon will appear next to the name of the device. If Device Manager cannot identify the device, it will label it an unknown device.
When a device is not working properly, Device Manager will also usually display an error message with an accompanying error code. There are many different Device Manager error codes. For an explanation of what each code means and a suggested solution to each error, go to the Explanation of error codes generated by Device Manager on the Microsoft Help and Support website.
When a device does not work properly, it is often due to a driver problem. For example, the driver might be missing or out of date. For more information, see Tips for fixing common driver problems.