Avira > A filter which can be turned off at will is not sufficient in halacha.
Even such filter might be useful. Search engines focus on more specific words you use. So if you use an unfortunate word, or even misspell something, then you suddenly get a lot of stuff that you never expected. Search engine filter reduce the problem but it might still happen.
So, for a lot of people, you put the right filters in and it is sufficient. As in any search, most people use default options for anything. If amazon sorts things by “popular item” by default, only minority of users will press the button “sort by cheaper price”.
For people who have bigger problems – a user should have a local account (non-admin), and another user should have an admin or parental account that installs filtering tools. Actually, for everybody: from cybersecurity point of view, you should have an admin account on your PC and use a different account for your internet browsing and email, even if you are using mehadrin filters. Less chances that sheidim will take over your computer.