to Cable Forum
Freeview is supplied over terrestrial (rooftop type) aerials.
The Virgin Media TV services do not carry freeview, but their own often encrypted signals. These can only be read by use of a Virgin Media Cable Set Top Box (STB). You need a current subscription with VM, where they will supply the STB as part of that subscription. Don't be tempted to buy a box off ebay or similar as STBs are hired, not sold, for VM cable and won't work if not part of a siubscription.