Did your system ever have a Pinnacle tuner in it? Some part of the system thinks it did and cannot find it.
But back to your problem...
You stated that you cannot get by the internet connection point of MC setup. That concerns me and makes me think it may be a firewall or network card problem that is your major problem. Make sure you turn off all firewalls. Many antivirus programs include a firewall so make sure they are turned off. Another option is to try a different net card in your computer.
Back to Pinnacle. I assume that you have checked the Device Manager and there are no Pinnacle tuners listed, right? If the tuner config is somehow screwed up, I would remove the tuner drivers for whatever tuners are there in Device Manager. Then reboot and the system will re-discover them and re-install the drivers.
Good Luck!
1: Dimension 9200 - Vista Ult, 2.4GHz Q6600 Core2Quad, 4GB RAM, 160GB, 750GB, 500GB USB, Nvidia 8300GS, PVR-150, HDTV Wonder, Vbox 3560, X360, DMA2100
2: HP m376n - MCE 2005, 2.6 P4 w/HT, 1GB RAM, 250GB, 400GB USB HD, Nvidia 6200, Emuzed MAUI, X360