I don’t think PC should be present on the TV’s ‘connections’ menu; it is usually just accessed by pressing PC.
I can confirm that is the case for an early model of BV6 I had.
On my current Beocenter 6 though the PC command can be choosen for any input, and the DVI connector is on AV3 but is shared with the component connectors. In the AV3 configuration I think you have to select HD or something like that to us the DVI connector. I cant get to the TV right now (sleeping child in front of it), but I can check up on it tomorrow if you don’t find it yourself before that.