My father is pretty careless about his security and this is not new. He even said to me that in the last year he used Tor to access some links just for curiosity because he read about it in some news and followed a tutorial on the internet to do this.
Last night, I used his PC and saw strange programs running and, in his history, that he accessed some adult sites and some strange URLs, too (probably from ads and pop-ups in these sites). Antivirus doesn't work because he clicks on everything.
I spoke with him many times but nothing has an effect and I'm tired of this. I have blocked all inbound connections in my PC's firewall, so I can't see anything suspicious, but my mother has her own PC and she is a very non-technical user, so it's not an option to install a firewall that asks about every new connection, and I don't have time to monitor her PC all the time. Furthermore, we all have our own smartphones, so even if our PCs are protected, the smartphones are not.
Is there a way that I can be free from this terrible headache and protect our devices? I don't have knowledge in networks, I don't even know if my worries are relevant, so I will appreciate non-technical language, if it is possible.
Unfortunately, my router does not support VLAN. Is there anything that I can do without this option?
Obs: all the devices are android or windows.