It looks as if getch() isn't in conio.h, but I got this to work with a bit of effort

Dev C++ ver 4.?

Code:
#include <iostream>
#include "C:\Dev-C++\Include\conio.h"

using namespace std;

int main(void)
{
   char letter;
   letter = getche();

   return 0;
}
Look in the conio.c and conio.h files for seeing what code is finished. It looks like some of the functs aren't et done.