I have silence on just installed WinTV and the fault, I am sure, is in my PC. Now using XP but was familiar with volume sliders in 98SE.
If I go Start/Accessories/Entertainment/Volume Control it says there are no active devices available. Go Control Panel>Click Printers>Other Hardware and then click Add Hardware. There is no Other Hardware.
Also if I go Control Panel>Sounds and Audio Devices it says No Audio Device and the rest is greyed out.
I recently did a full install and was thinking of other problems (same PC) and I forgot to install some stuff. I have installed SoundMAX Digital Audio and my sliders have returned. I'll check it when its finished installing the other stuff. I always thought the sliders were part of Windows.