Virus scam received via WiFi

I am constantly being bombarded, on my Dell laptop, by spoof messages appearing directly in both Chrome and Edge browsers - not emails.  These messages claim that I have been infected with a virus and that I need to click on a link (with a ".in" suffix!) to remove the virus.  Needless to say, I have ignored this advice.  The messages will cease for a while and then return.  I do have AVG Anti-Virus free installed and also Widows Defender (Win10) claims to be protecting me, but neither appear to be effective.

My wife's IPad, using the same router, is unaffected.

Interestingly, whilst typing this, I am not getting any spoof messages.