MikTeX is a magnificent and very user-friendly Windows distribution for TeX, but for various historical reasons, mainly due to lack of LuaTeX, ConTeXt has been broken in MikTeX for a long time. Unless you have some ancient MikTeX with ancient ConTeXt lying around, ConTeXt will only work with MikTeX 2.9 (or later; at the time of writing no newer version exists) that includes LuaTeX 0.70.1.
... will become available once ConTeXt starts working ...
As of end of June 2011 MikTeX is still (or again) non-functional. This will hopefully be fixed soon (you can already replace the version of ConTeXt by your own), however some problems with ConTeXt MKIV will remain:
- ConTeXt MKIV will never be up-to-date and will hardly ever be hot-fixed.
- MikTeX only updates binaries every now and then. Since ConTeXt MKIV strongly depends on LuaTeX version, ConTeXt cannot be updated arbitrarily and the updates may become out-of-sync with currently included LuaTeX version. If that happens, ConTeXt stops working.
- MikTeX now ships for two architectures: 32-bit and 64-bit. If LuaTeX gets out-of-sync on those two, ConTeXt will necessary be broken on at least one of them.
- Hans likes to reimplement every bit and piece of standard TeX installations (like kpathsea, texmf.cnf, ...). This has two major consequences:
- Author of MikTeX may not always be aware of modifications and might implement requirements for these features with delay. In the meantime ConTeXt might become broken.
- Download of packages on request doesn't work with ConTeXt MKIV. The feature is hooked into kpathsea, ConTeXt doesn't use kpathsea, but doesn't provide any alternative for this either.
- For all of the reasons already mentioned, the number of ConTeXt users on MikTeX is very small which means less testing and more problems.