How do you stop apps being installed

Hello Grahame,
We suggest you to provide screen-shot (http://avgread.me/1aZxsAV) of the pop-up notification which will help us in identifying the type of pop-up. Thank you.

When I am connected to WiFi, a notification from Avg appears sometimes saying 10 drops safe to open, or Insane Stars threat detected. I immediately uninstall them. My question is, how do I prevent them from being installed?

Hello Pam,

The instructions are provided in the link provided by Rajarajan previously.
Please follow that and take a screenshot and attach it here.
Just in case that you are unaware, you can post the screenshot here in your topic. Click on 'Answer' & then click on the 'Image' [mountain symbol] & follow the instructions.

Hello Grahame,
We suggest you to provide screen-shot (http://avgread.me/1aZxsAV) of the pop-up notification which will help us in identifying the type of pop-up. Thank you.

How do I do a screen shot?