I hope this does not open another thread with the same name, but I did not find a way to respond directly within the archive--something else I am missing or will ntg find the reference? Here it goes...

Thank you for response luigi. The story:

OS = Windows7 professional
I also have MikTeX installed which I use routinely for pdfLaTeX and METAPOST from TeXworks

download context-setup-mswin.zip from the wiki
unzip to  C:\context 
run from shell  C:\context>first-setup.bat --modules=all
add to PATH  C:\context\tex\texmf-mswin\bin\ 
run from shell  C:\context>first-setup.bat --keep

Then create tex file \starttext Hello world \stopptext  in different location.

Navigate shell to that location and  >context firstfile.tex 

Result is  message
context: The Lua script is not registered.
context: Data: context

Aha! I tried moving firstfile.tex into C:\context and then run and it works, but takes 11.62 seconds--not so good.

However, I still get Lua script not registered when I try to run from other file locations, which makes me think it is PATH problem that I will continue to chase but if anything looks obvious please help.

--johnk