Thanks very much!!!

Any luck with that approach?

C:/Ruby192/bin/ruby.exe extconf.rb
checking for ffi.h… *** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of
necessary libraries and/or headers. Check the mkmf.log file for more
details. You may need configuration options.

Provided configuration options:
–with-opt-dir
–without-opt-dir
–with-opt-include
–without-opt-include=${opt-dir}/include
–with-opt-lib
–without-opt-lib=${opt-dir}/lib
–with-make-prog
–without-make-prog
–srcdir=.
–curdir
–ruby=C:/Ruby192/bin/ruby
–with-ffi_c-dir
–without-ffi_c-dir
–with-ffi_c-include
–without-ffi_c-include=${ffi_c-dir}/include
–with-ffi_c-lib
–without-ffi_c-lib=${ffi_c-dir}/lib
–with-libffi-config
–without-libffi-config
–with-pkg-config
–without-pkg-config
C:/Ruby192/lib/ruby/1.9.1/mkmf.rb:368:in `try_do’: The complier failed to generate an executable file. (RuntimeError)
You have to install development tools first.
from C:/Ruby192/lib/ruby/1.9.1/mkmf.rb:452:in `try_cpp’
from C:/Ruby192/lib/ruby/1.9.1/mkmf.rb:834:in `block in have_header’
from C:/Ruby192/lib/ruby/1.9.1/mkmf.rb:693:in `block in checking_for’
from C:/Ruby192/lib/ruby/1.9.1/mkmf.rb:280:in `block (2 levels) in postpone’
from C:/Ruby192/lib/ruby/1.9.1/mkmf.rb:254:in `open’
from C:/Ruby192/lib/ruby/1.9.1/mkmf.rb:280:in `block in postpone’
from C:/Ruby192/lib/ruby/1.9.1/mkmf.rb:254:in `open’
from C:/Ruby192/lib/ruby/1.9.1/mkmf.rb:276:in `postpone’
from C:/Ruby192/lib/ruby/1.9.1/mkmf.rb:692:in `checking_for’
from C:/Ruby192/lib/ruby/1.9.1/mkmf.rb:833:in `have_header’
from extconf.rb:9:in `’

Gem files will remain installed in C:/Ruby192/lib/ruby/gems/1.9.1/gems/ffi-1.0.11 for inspection.
Results logged to C:/Ruby192/lib/ruby/gems/1.9.1/gems/ffi-1.0.11/ext/ffi_c/gem_make.out