In the bios you can enable or disable your serial ports - you have to press F2 or DEL to enter the setup. Try looking under Intergrated Peripherals to see if COM 1 and/or 2 are enabled - which they should.
An easier and much better way to network two computers is using a 10/100 network card and a cross-over cable. This is much faster and you can share resources, files, and internet.