Hello Wolfgang,
I think I´mgetting confused with all of the font selection within context.
You are not the first one...
First: I have a miktex environment on on W2K.
That should be OK for all needs.
1. to change single fonts:
see http://contextgarden.net/Psnfss
\definetypeface [palatino] [rm] [serif] [palatino] [default] [encoding=ec] \switchtotypeface[palatino][12pt,rm]
I have never used \switchtotypeface.
2. I thought that the default encoding should be texnansi
This depends on your setup. See cont-sys.tex as a place where defaultencoding is sometimes set.
3. should be there some font-switching macros on the system called font-xxx.tex (example font-lbr.tex)? These are missing on my system. I think these are needed forthings like: \setupbodyfont[lbr, sans, 12pt]
Well the font-xxx.tex files have nothing (not completely true) to do with the font switching commands.
4. within miktex there are "lucida" font files from yandy (lbr.tfm ). Is that a free version of lucida-font?
No. There is no really free version of lucida. They once came with staroffice and there was a script that was able to pull them out and make them accessable for TeX. But I think that the quality is lower than the original ones (once read a statement from Walter Schmit about them, don't remember when and where) and math is not included.
(is that for math? [there is anotherfile called math-lbt.tex in \context\base])
No math fonts like lucida for free.
do I need to get the missing fonts/files and why are they not provided with miktex. Perhaps a change of the distribution is to prefer? (which one)
No, go ahead with MikTeX. Try out the stuff that is on the wiki and please report on your success/failure.
Is there a manual which explains how to change fonts (in a way that a normal user who is new to context can understand it)?
yes and no. See the wiki for links. Patrick -- ConTeXt wiki: http://contextgarden.net