Go to: Drive Letter:Program FilesSteamsteamappscommonskyrimData<br />

For those who don't have bought the game on steam, the SkyrimPrefs.ini file is located in Drive Letter:Users<USERNAME>DocumentsMy GamesSkyrim<br />

<br />

1. Drop the 'killable_children.esp' in that folder<br />

2. Launch the Skyrim Launcher, and click on 'Data Files'<br />

3. Tick 'killable_children.esp' and click 'Ok'