What are you seeing?
A yellow exclamation mark on a PCI Serial Port in Device Manager.
Why are you seeing it?
The Intel® Active Management Technology (Intel® AMT) drivers aren't installed.
How to fix it
To eliminate the error, install the Intel AMT drivers. You aren't required to enable Intel AMT in the BIOS. You can install the drivers from either the CD or DVD that came with your Intel® Desktop Board, or from Download Center.