How To stop Your Child Kids brother Sister From Downloading Porn Adult Sex Videos?

Out of the options you have this maybe the best one:
You can always put a parental lock on the computer, basically what this does is it lets you restrict which websites and programs the users on the computer can use. You need to make sure you're a administrator and you have a user account for your Child Kids brother Sister. This feature only works if your Child Kids brother Sister logs in using the user account, so don't leave your administrator account on or tell him the password. In this way, you get a weekly report on the websites and programs he has been using.

This is how you enable it:

1. Click on the top left-hand corner
2. Open 'Control Panel' from the sidebar
3. On Windows 7, you should see 'Users and Family safety' on the top right, If you're using a different windows version, search "Family safety" on the search bar and it should come up.Once you're on the Family and safety, it should be simple from there onward.

Another Way:
Delete all the porn he's downloaded - be sure to use something like AVG to delete it completely (so it's not recoverable)

If you have any questions, feel free to ask me!