Issue #1668 has been updated by Kristian Mandrup. Turns out the fix is here: http://blog.orangecabin.com/2009/05/install-ruby-1-9-on-windows-using-zip-binary/ Download the file First you download the 1.9 package from http://www.ruby-lang.org/en/downloads/ Choose ¡ÈRuby 1.9 xxx binary¡É instead of ¡ÈRuby xxx Installer¡É. Install it Just Unpack the zip to c:\ruby. Then add c:\ruby\bin to windows PATH. Open a windows command console and type gem update --system Oops, it is broken! The binary is missing some dll files. Let us fix it zlib Download zlib windows binary from http://gnuwin32.sourceforge.net/packages/zlib.htm unzip the package, then find a file named ¡Èzlib1.dll¡É. Copy ¡Èzlib1.dll¡É to your ruby\bin directory AND rename it to zlib.dll What the heck?! Why renaming it? Because ruby source code reference the dll as zlib.dll. It is common to use alias like this on Linux. Ruby source was coded on Linux. openssl Download openssl windows binary from http://gnuwin32.sourceforge.net/packages/openssl.htm Unzip it. Find ¡Èlibeay32.dll¡É, copy to ruby\bin. Don¡Çt rename it. Find ¡Èlibssl32.dll¡É, copy to ruby\bin and rename it to ssleay32.dll readline Download readline windows binary from http://gnuwin32.sourceforge.net/packages/readline.htm Unzip it. Find ¡Èreadline5.dll¡É, copy to ruby\bin and rename it to readline.dll Done That is all. Now type gem update --system then gem install rails It works :) Would be nice if these renamed DLLs were included with the ruby binary zip and also included a small install note for windows. ---------------------------------------- http://redmine.ruby-lang.org/issues/show/1668 ---------------------------------------- http://redmine.ruby-lang.org