HyperTerminal is a serial (and network) communications program that is included with Microsoft Windows(tm), though it may not be installed by default. It can typically be executed by clicking on the "Start" button, then selecting "Programs", "Accessories", "Communications" (sometimes you can skip this one), "HyperTerminal".
If HyperTerminal is not installed, you can install it from your Microsoft Windows CDs by clicking on the "Start" button, then selecting "Settings", "Control Panel", "Add or Remove Programs", then "Add/Remove Windows Components" (this is typically on the left edge of the dialog). That will open another dialog titled "Windows Components Wizard". HyperTerminal should be listed there.
To use HyperTerminal to communicate with a TCB using a serial connection, you will need to set up HyperTerminal to connect using COMx, where "x" is a serial port in your computer. That setting can be found in the "File", "Properties" menu.