Testing the keyboard buffer for MT/Not MT

I've been trying to use _kbhit() but it didn't do what I thought it 
would from books, "Detects whether a keypress is available for reading."

Herbert Schildt says,
"If the user has pressed a key, this function returns
true(non-0), but does not read the character.
If no keystroke is pending, kbhit() returns false (0)."

Here is the test code,

#include<conio.h>
void main(void) {
         int ig1=0, ig2=0, ik=-1;
         ig1 = _getch();
         ik = _kbhit();
         ig2 = _getch();
         _getch();
         printf("ig1=%d, ik=%d, ig2=%d", ig1,ik,ig2);
         return;
}

Whatever keys I press a runtime, ik returned as 0. Where else would a 
keystroke be "waiting" except in the buffer?  If _kbhit() does not look 
at the buffer, what does it look at?