Eric Hodel wrote: > You need the MS C compiler. Well, now I've downloaded and installed Visual C++ 2005 express edition in order to get that. I also upgraded the RubyInline gem to the latest, greatest 3.6.0 version. I set INLINEDIR to INLINEDIR=C:\ruby\lib\ruby\gems\1.8\gems\RubyInline-3.6.0\demo To verify that the C-compiler is operational, I commandline-compiled the following example provided by Microsoft. #include <iostream> int main() { std::cout << "This is a native C++ program." << std::endl; return 0; } with the line: cl /EHsc simple.cpp after running the env var setup script they refer you to. That all works fine. So, anyway, here is what RubyInline gives me now ... C:\ruby\lib\ruby\gems\1.8\gems\RubyInline-3.6.0\demo>ruby hello.rb cl : Command line warning D9035 : option 'Og-' has been deprecated and will be r emoved in a future release cl : Command line warning D9035 : option 'o' has been deprecated and will be rem oved in a future release cl : Command line warning D9002 : ignoring unknown option '-G6' c:/ruby/lib/ruby/gems/1.8/gems/RubyInline-3.6.0/./inline.rb:404:in `build': erro r executing cl -nologo -LD -MD -Zi -O2b2xg- -G6 -I c:/ruby/lib/ruby/1.8/i386-ms win32 -o "C:\ruby\lib\ruby\gems\1.8\gems\RubyInline-3.6.0\demo/.ruby_inline/Inli ne_Hello_5d41.so" "C:/ruby/lib/ruby/gems/1.8/gems/RubyInline-3.6.0/demo/.ruby_in line/Inline_Hello_5d41.c" -link /LIBPATH:"c:/ruby/lib" /DEFAULTLIB:"msvcrt-ruby 18.lib" /INCREMENTAL:no /EXPORT:Init_Inline_Hello_5d41: 512 (CompilationError) Renamed C:\ruby\lib\ruby\gems\1.8\gems\RubyInline-3.6.0\demo/.ruby_inline/Inline _Hello_5d41.c to C:\ruby\lib\ruby\gems\1.8\gems\RubyInline-3.6.0\demo/.ruby_inli ne/Inline_Hello_5d41.c.bad from c:/ruby/lib/ruby/gems/1.8/gems/RubyInline-3 .6.0/./inline.rb:624:in `inline' from hello.rb:7 Hmmm. Am I getting closer? BTW. I am using the "One-Click Ruby Installer for Windows" as my Ruby installation. Thanks for any help, -- Mike Berrow -- Posted via http://www.ruby-forum.com/.