[NTG-context] ConTeXt in texlive

Hi all, I have some problem when using ConTeXt in tl08, when I type luatools --generate my cmd windows says like this

C:\Users\fnsteed>context --make

MtxRun | error unable to locate texmfcnf.luaShould I create the cache path C:\Us ers\fnsteed\? [yes|no] [no] y

fatal error: there is no valid cache path defined

or like this

C:\Users\fnsteed>luatools --generate

LuaTools | error unable to locate texmfcnf.lua LuaTools | loading d:/texlive/2008/texmf/web2c/texmf.cnfShould I create the cach e path C:\Users\fnsteed\? [yes|no] [no]

fatal error: there is no valid cache path defined

I don't exactly know what that means but clearly I cannot use ConTeXt. Can someone help me? Thanks. Cheers; Fengnan