In a new computer system or on an upgraded motherboard, you will have to use the serial port cables supplied along with the board to connect the serial connectors at the back of the system case.
These cables are not universal i.e., after upgrading the motherboard if you leave the old cables as such and connect them to COM1 or COM2 port headers on the new motherboard, these ports may not work. Do note that these headers are not present on the new ATX motherboards.
