Computer Device Manager has an unknown device (yellow question mark) how to solve

1. By obtaining the hardware ID method, carries on the contrast confirmation, carries on the drive downloading installs

(1) Open Device Manager, find the following logo yellow exclamation point device, the following illustration illustrates, in the "Network controller" click on the Mouse "right" to choose "Properties";

(2) Find "Details" and select the "Hardware ID" option in the property option;

(3) Please download the corresponding drive provided by the official website for related downloads.

Device Name	corresponding Hardware ID	Device corresponding driver name
Unknown device	acpipnp0c311	TPM Driver
	ACPIWEC10001	Tpm
	ACPILBA0001	ACPI Driver
	usbvid_1926&pid_1843&rev_0008	Nextwindow Touch Driver
	ACPILBAI01001	Lenovo Service Engine
PCI serial Port		AMT Drive
PCI Simple Communication Controller

2. Use music drive automatic installation drive

(1) Download Le drive, install the related drive. Click "Use tool to install driver automatically";

(2) Click "Free download", download le drive for installation;

(3) The driver will automatically detect, find the corresponding driver, select the corresponding driver to install it.

If the above solution does not solve your problem, we can go to http://www.drivergenius.com/to download a drive wizard to solve your problem.