C:/InstantRails/ruby/bin/ruby.exe extconf.rb install curb
checking for curl-config... no
checking for main() in curl.lib... no
*** 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
        --srcdir=.
        --curdir
        --ruby=C:/InstantRails/ruby/bin/ruby
        --with-curl-dir
        --with-curl-include
        --without-curl-include=${curl-dir}/include
        --with-curl-lib
        --without-curl-lib=${curl-dir}/lib
        --with-curllib
        --without-curllib
extconf.rb:9:   Can't find libcurl or curl/curl.h (RuntimeError)

  Try passing --with-curl-dir or --with-curl-lib and --with-curl-include
  options to extconf.


Gem files will remain installed in C:/InstantRails/ruby/lib/ruby/gems/1.8/gems/curb-0.4.4.0 for inspection.
Results logged to C:/InstantRails/ruby/lib/ruby/gems/1.8/gems/curb-0.4.4.0/ext/gem_make.out