gentoo mount from sysrccd

swapon /dev/sda2
mount /dev/sda3 /mnt/gentoo
mount /dev/sda1 /mnt/gentoo/boot
mount -t proc proc /mnt/gentoo/proc
mount -o bind /dev/ /mnt/gentoo/dev
Once inside the chroot you need to run
chroot /mnt/gentoo /bin/bash
env-update
source /etc/profile

gcc in windows (test on xp)

Warning: this is not for NooBs
Do this at your own risk.

get gcc for windows
http://gcc.gnu.org/install/binaries.html

download and install

Microsoft Windows:

* The Cygwin project;
* The MinGW project.

set the path in environmental variables:
;C:\MinGW\bin;

put c code in a folder
c:\mkdir ccode
// put this code in that folder

<> >gcc on windows (tested on windows xp)
pu c code in this folder
c:\mkdir ccode
// put this code in that folder
//start of hello world "hello.c"

#include <stdio.h>

int main (void)
{
printf ("Hello, world!\n");
return 0;
}
// end of code hello.c

to compile:
cd c:\ccode\
c:\gcc hello.c -o hello
to run
c:\hello


// here's some simple math code
//program1.c

#include <stdio.h>
#include <math.h>

int main(void)
{
       printf("%.0f\n", sqrt(4));

       return 0;
}
//make sure to add a new line at the end