Anyone else have an annoying hum after install?...
As said, this will be very likely be the result of the wire connecting the sound card to the TV card picking up noise. If it's real bad there might be a problem with either the computer's or the antenna cable's earth.
Double click on the speaker icon in system tray and disable the input you used on the souncard (for me it's 'aux', for example).
As for the PCTV being difficult to install, I'm pretty sure it's "only" a driver issue. AFAIK this is just another card based on the Bt848, just like the now ancient orginal Happauge WinTV PCIs, which work just fine with XP.