Rubygem zlib.dllとか
方法
http://www.rubylife.jp/railsinstall/rubygems/index3.html
DL先 zlib.dll
http://sourceforge.jp/projects/sfnet_bleachbit/downloads/gtk/2.16.4/zlib123-dll.zip/
DLLの偽物だらけで、さがすの面倒だったのでメモ
"ssleay32.dll", "libeay32.dll", "readline.dll", "pdcurses.dll", "gdbm.dll", "incov.dll"
http://www.garbagecollect.jp/ruby/mswin32/ja/documents/install.html
http://konohaotoshi.blog69.fc2.com/blog-entry-118.html
http://jp.dll-download-system.com/dlls-download-l-/libmysql.dll.html