Htpc tuner issue with cable system...

Sounds like you need to find out what your cable company's boxless lineup is. Assuming your cable company is like most and has gone all-digital (no analog broadcasts) then all of your channels are going to be something like 34-1, 34-2, 34-3, etc. As an example, here is my carrier's boxless lineup:

http://www.myinsight.com/documents/boxless_channellineup_ken.pdf

This is information that WMC is not aware of, so you'll have to go into the settings for WMC and manually tell it where to find each channel.

That is done via Tasks > Settings > TV > Guide > Edit Channels.

It should display a list of all channels it has detected a signal on. If not, have it run a channel scan again.

Basically what you'll have to do is go down the list and look for channels that are either missing from your guide or do not have correct guide data. If they are not in the guide, the check box will be blank. If they are in the guide but there is no listing data, they will have a check mark but the listing data to the right will be incorrect.

Once you find a channel that needs to be corrected, click on the listing data box to the right of the channel number, and then click Edit Listings. Then you will have a list of all listings available for your selected cable company/market, and you'll have to scroll through it and pick the right one for that channel. To speed things up, you can type the first few letters and it will take you to that part of the list.

Once you select the correct listing, you click Save and then move on to the next channel, etc.

Not sure what you're asking. If you don't use a cable box or a cablecard tuner, then you're going to see channels like 2.1, 2.2, etc. There's no way around it. It's not a matter of updating software or anything like that--that's just the way the system is.

A channel without a dot (or dash or whatever you want to call it) is going to be an analog channel. It's the same whether you're using an HTPC or a modern TV. Without a box, you have to use the dotted channels.

I have no answer for that, as it makes no sense at all to me. I have the same channels on my HTPC that I have on my TV. I can see no reason why they would be different, unless one is using a cable box and the other is not.