I downloaded the Emsisoft Emergency Kit. Ran the program and deleted everything. But I am still getting ads. I don't think it is necessarily a virus; he plays a lot of computer games but doesn't really download much. I also downloaded adblocker for Chrome. Still getting ads.
Can't you read?
1. Install Eset Smart security and apply the child safety lock included in it.
2. Use Malwarebytes to get rid of the crap
3. Install CCleaner and remove all the left over shit, and fix the registry at least 3 times over.
4. Tell him that his days with porn and warez is gone.
Or you can download all kind of crap and futile software, which may be adware itself. In fact, you should start by scanning the computer with some reliable online scanner, like F-secure, House Call by Trend Micro or Eset. Don't hesitate to start at least two of those at the same time. When You are sure that there isn't any viruses, continue from stage 1.