[This is preliminary documentation and subject to change.]
The following command line syntax toggles WebTV for Windows between windowed and full-screen display. If WebTV for Windows is not currently running, this command line also starts WebTV for Windows.
<path>Tvx.exe -t
Where
HKLM\Software\Microsoft\TV Services
If you are running the command line from the WebTV for Windows directory, you do not need to specify the path.
The following line toggles the WebTV for Windows display mode. If WebTV for Windows is displaying as a windowed application, the command causes it to display full-screen, and vice versa.
C:\Program Files\TV Viewer\Tvx.exe -t