If a "PCI Serial Port" driver is missing in Device Manager, you need the Chipset or Serial Port driver from your motherboard manufacturer . To narrow this down, please tell me:
Are you trying to connect an or a USB-to-serial adapter ? Driver Communication Port Com1
If this fails, download chipset drivers from your motherboard or laptop manufacturer’s support site . 3. Change a Device to use COM1 If a "PCI Serial Port" driver is missing