I have a problem. Many have the same question but I didn't find the answer.
I installed gcc-4.9.0 on my PC but Eclipse won't find it. I used the default installation path:
C:\MinGW
For more information, see: http://wiki.eclipse.org/CDT/User/FAQ#I_installed_MinGW_toolchain_on_my_PC_but_Eclipse_won.27t_find_it.