error site is not safe

[SherryC47]

We have a new Netgear router.  we can't use 3 of our computers including 2 fairly new  HP laptops.  We get site not safe message on all sites. We spent a couple of hours with Netgear support including a session with the second level tech.  They could find nothing wrong with the router.  Husband is desperate as he uses his for business.  We also spent a long  time with Spectrum with no answers.   Netgear and Spectrum  told us our computers were the problem.

We have 3 HP computers:1 desk top and 2 almost new laptops.  The only change made was installation of Netgear moblie app into husband's phone. 1 laptop has Windows 11, the other laptop and desktop are Windows 10 64bit.   We are in our late 70's and are moderately computer literate.

Thank you

[banhien]

@SherryC47 

You have to set this up from Browser, for example for Chrome

                https://support.google.com/chrome/answer/95617?hl=en

Regards.