"Open with" for .tab files not doing anything.

I’m trying to associate “.tab” files with LibreOffice. I’m doing this one of two ways. The first by right clicking a .tab file, selecting “Open with”, “Choose default program…” giving the open with window. If I then click “Browse…” and select the LibreOffice Calc progam it returns to the “Open with” window, having done nothing.

Selecting a default program through the control panel does essentially the same thing.

I am running windows 7.