I/O redirection. Is the problem with my compiler or with my OS?

[jadumonium]

I keep on getting errors while trying to do file redirection.
I wrote the following code to test if the problem is with the complexity of my other programs or just the compiler.

#include <stdio.h>
int main()
{
	int x;
	scanf("%d", &x);
	printf("%d", x);
	return 0;
}

Input is 4. Output should also be 4.
When I first tried doing it in the usual way, it worked. But when I tried file redirection, I got a long series of numbers. Idk if it's the address of the input or what.

Here's what I got:

File in.txt contains just the number 4.

I tried doing this in our lab; it worked perfectly fine.
I use MinGW compiler and my OS is Windows XP.
Also, what could be the problem if it's neither the compiler nor the OS? :/

[Salem]

Well you could try this, to perhaps help with diagnosis

#include <stdio.h>
int main()
{
	int x = 0;
	int r;
	if ( (r=scanf("%d", &x)) == 1 ) {
		printf("%d\n", x);
	} else {
		printf("scanf failed, returned=%d\n",r);
	}
	return 0;
}