I have the 64-bit version of Eclipse Helios SR1 with CDT on Windows 7 64-bit. I am using MinGW as my toolset. I have an environment variable set under Project > Properties > C/C++ Build > Environment for PATH that points to "c:\mingw\bin". Eclipse is set to Append these environment variables.
When I try and build with this configuration, I get:
Internal Builder: Cannot run program "gcc" (in directory "C:\Users\<me>\workspace\test\Release"): CreateProcess error=2, The system cannot find the file specified
Build error occurred, build is stopped
When I quit out of Eclipse and manually set my PATH environment variable in Windows to include "c:\mingw\bin" (through System > Advanced System Settings... > Environment Variables...) everything compiles fine without changing any of the options in Eclipse.
TLDR: The only way I can get my project to build is by setting my environment PATH variable manually through Windows -- the Eclipse-set environment variables aren't taking.