Weird setup problem...

Hi - I have a new HP, which comes with a TV tuner. I do not have a decoder -
I just plug the cable directly into the computer.

I only get channel 5&6. The cable company was out here yesterday. It works
fine on their TV.

I did a bit of searching. Somewhere i found a trouble shooting guide for a
cable convertor box. If you only get channel 5&6 it means you have to switch
the STD/HRC switch on the cable box. Al good, except I dont have a box.
Anyway to change this any other way?

I should mention one of my TVs does this too, but I got around it by
watchinthru a VCR.

Thanks