I seem no to be able to use system fonts, not with /simplefonts neither with typescripts. When I define

\starttypescript [serif] [arnoproregular]

\definefontsynonym [Serif] [name:arnoproregular]

\definefontsynonym [SerifItalic] [name:arnoproitalic]

\definefontsynonym [SerifBoldItalic] [name:arnoproitaliccaption]

\definefontsynonym [SerifCaps] [name:arnoproregular]

\stoptypescript

(or any other system font in my Windows font directory e:/windows/ fonts as defined in osfontdir), I get

fonts           > typescripts > unknown library 'loc'
{E:/texprogs/texlive/2013/texmf-dist/fonts/map/dvips/lm/lm-math.map}{E:/texprogs/texlive/2013/texmf-dist/fonts/map/dvips/lm/lm-rm.map}{E:/texprogs/texlive/2013/texmf-dist/fonts/map/pdftex/context/mkiv-base.map}
fonts           > 'fallback modern rm 11pt' is loaded

First, I don't understand "unknown library 'loc' " > I haven't defined that. Or does it mean 'local'? When I do the same with, say, garamond, I also get the line "unknown library 'garamond' " > why does it think garamond is in a library?
When I do

mtxrun --script fonts --list --info --pattern=arnoproregular*

mtxfonts gives me all kinds of information, so the font *is* known to ConTeXt. Or is that a rash conclusion?

Second, there is not even a mention of the typescript or the font in the log. Why is that? Is it purely a syntax error in my setup as copied above?

Thirdly - of course - my question is: how can  I  make ConTeXt use my system fonts?

I use TexLive (most recent version), Texworks and Windows 7. Before I had a standalone ConTeXt set-up, which gave the same problems.

Regards,

Sven Huynink