The question is: what have you set OSFONTDIR to, and does that location actually contain the system fonts?
Thank you, Taco. Double checking, I find that I have set OSFONTDIR to C:\Windows\Fonts, which does indeed contain my 1074 system font files, 970 of them open type. The slightly different string you put on the webpage: mtxrun --script fonts --list --all --pattern=* now seems to find them. That was the problem. My next problem is to make sense of what lies under the heading "The standard way: Typescripts". It's clear that the instructions don't mean "typescript" in the ordinary English sense of the word (a typewritten document), but some new, undefined thing. From other bits of documentation here and there, I've gotten the idea that typescripts are files that contain commands. I know that there are examples of typescripts given elsewhere, but without explanation, I couldn't decipher them. I don't suppose there is a syntax of the typescript language written down anywhere. The first instruction stymies me: "1. Copy the typescript files into either $TEXMF/tex/texmf-fonts/tex/context/user $TEXMF/tex/texmf-project/tex/context/user" What typescript files? Where? Also, the two directories don't exist in my distribution of Context Minimals. Are we supposed to create them? I look ahead for clues as to where the typescripts for my fonts might be. A little farther down there is a heading, 'Where to find existing typescripts', but it doesn't talk about where to find typescripts. It does hint at what typescripts are though---it says, 'Each of the typescripts below...' and then, below, there is a list of lines like the following: Latin Modern (typescript name: modern; this is the default font set) Maybe a line like that is a typescript. Who knows?