I hope it is a simple question.

1. I have Ceton InfiniTV 6 PCIe, Comcast.
2. I configured my HTPC setup to watch my TV programs, and it was working just fine.
3. Later I added another PC, where I put WMC extender, and configured this setup successfully to watch my TV. It still works just fine.
4. After I added the extender, my main WMC stopped working. I think it says cannot find tuner.

I would like to watch my TV on both PCs, how can I fix the problem?

All is on Windows 8.1 professional.