the ftplugin for vim *.inf files defaults to inform which says something about a Z-machine. Needless to say, this provides the wrong syntax highlighting etc for a windows .inf device driver file.
The format of the Windows driver information files is (similar to) that of *.ini
files, and Vim has a syntax script for that.
:setf dosini
To change the automatic detection, put the following into a ~/.vim/filetype.vim
script:
if exists('did_load_filetypes')
finish
endif
augroup filetypedetect
autocmd BufNewFile,BufRead *.inf setf dosini
augroup END