Ruby - JSON 1.8.2 won't build with "rails new" command

I'm currently running 64-bit Windows, and I'm trying to use "rails new". When I do, I get this error:

C:/Ruby22-x64/bin/ruby.exe -r ./siteconf20150323-1220-19w50c0.rb extconf.rb creating Makefile

make "DESTDIR=" clean

make "DESTDIR=" generating generator-x64-mingw32.def /bin/sh: /C/Ruby22-x64/bin/ruby: No such file or directory Makefile:260: recipe for target 'generator-x64-mingw32.def' failed make: *** [generator-x64-mingw32.def] Error 127

make failed, exit code 2

I can't find the Makefile anywhere, and this may be a Cygwin problem. Does anyone know how to fix this?