@exvion said:

breton_nerd, i use this version of ruby http://rubyforge.org/frs/download.php/47082/ruby186-27_rc2.exe for compile C++ extension.
And I comment lines
//#if _MSC_VER != 1200
//#error MSC version unmatch
//#endif
in c:\Ruby186\lib\ruby\1.8\i386-mswin32\config.h
I had failed with other versions. What version of ruby you use?

Yes that is Ruby version 1.8.6-p287, the version of the interpreter that Google distro'd with Sketchup 8.x;
(The 27_rc2 refers to the One-Click Ruby Installer release package.)
Here is the Release Notes page link.