Try editing the setup.ini file in the drivers. InstallTvApp=FALSE change to InstallTvApp=True and install drivers.
Perhaps I'm missing something here Andrew, but why do you particularly need TV4PC? There are several other programs around which do the same if not better job, Mytheatre or ProgDVB are far superior TV interfaces.
the setup.ini is located in the 428TS driver Install folder the same folder as the setup.exe file. Just installed with InstallTvApp=True and TV4PC was installed.
If you are running Windows XP, MyTheatre is the best (in my opinion), This should be a working link. These programmes will knock spots of TV4PC, it is next to useless and only included as a utility, that's why they now include DVBViewer, unfortunately, this stands just behind TV4PC in the useless queue.