This worked for me on 64-bit install of Eclipse on Windows 7 using MinGW:
Right-click on your project. Select “Properties”.
Select the “Run/Debug Settings” Property on the left of the new window.
In the right window, click on your executable to highlight (ie – Test.exe) and click “Edit”.
In the Environment tab, hit “New”
Name: PATH
Value: Path to your MinGW bin directory. (For me this was: C:\devcore\MinGW\bin
)
Click “OK” on all windows to close down.
Try running again, it should print output to the screen.