[JohnWB]

I have a windows 7 PC which has an internal Peak DVB-T 2 TV tuner which works fine in windows.

When I fire up Kodi there is no sign of it, what do i have to change / install to be able to use it.

[Jönke]

A backend, wmc, dvbviewer or similar. Kodi is not a pvr programme, it only connects to a backend.
See wiki for more info

[RockerC]

The basics on how PVR works in Kodi is mostly explained in the wiki here http://kodi.wiki/view/PVR and here http://kodi.wiki/view/PVR_backend

If you already using WMC (Windows Media Center) then you can begin by trying http://kodi.wiki/view/ServerWMC as backend