Hi Roy,
You will need to give some more information on your system specs. Fill in as much information as you can.
There are several ways to connect. There are posts all over this forum referencing various models and types of tuner cards. The basic setup is to choose a tuner and install it in your system - you'll get what you pay for here so do some research in this forum to see what is working well for others. For example, I am extremely happy with my setup - it worked well when I was on cable and it works just as well now that I am on an antenna.
You'll also need to choose either a wireless keyboard/ mouse and/or usb remote control if you are going to use this away from a desk. This is not necessary to get started but you'll eventually want these items once you're up and running.
Once you have the hardware installed you have a couple of choices - if you are going to use the tuner only within Media Center, then just open Media Center and go through the setup in the settings menu, an easy to use, step by step process.
If you are going to use the tuner in windows also (other than media center or in a dual boot configuration) then you will need to install the software for the tuner card also. In either case you will want to set up the tuner in Media Center.
This forum is an excellent place to get the information you need to have a great experience with windows 7. Search the forums for answers to your questions and if you do not find what you are looking for, just ask.
I hope this helps you get started. Keep us posted here.
