Windows中的Ruby on Rails：安装DevKit时出错

I'm new in ROR and I'm trying to install DevKit but I get some errors. I use Win7-64bit and i installed DevKit-mingw64-64-4.7.2-20130224-1432-sfx. I followed the installation in github. Honestly, the errors are not clear and I can't find out what I should do to fix the problem.I'm new in ROR and I'm trying to install DevKit