To test the comport, you can make a simple " loop back test". On the viper cable there are 3 wires Black, Brown and White. Jump the Brown and White wires (TX and RX) together and then anything you type gets echoed back on the screen. (I just tested this and it works).
Also check if Comm 1 is enabled in the BIOS.
Do you have an other computer you can try ?
Al, there are also some shareware programs that are better than hyper term too.