Can't display internet pages

My friends Acer laptop can't display web pages any more ...

It can talk to the web , web sites ping back ok, a fresh install of Firefox has the same problems as explorer. It can't even display the web page of the modem / router (though other PCs can, again its there, I can ping it etc) . i've tried all the options on the Microsoft page (disabled services, apps, reset Explorer renewed IP, looked at the hosts files, etc etc) .. no joy.

It does work in networked safe mode and rolling back Windows to a previous restore point works also and as long as i never update Windows it'll be ok. Obviously I could try and pin it down to exactly which update did the damage by trial and error but that'll take a lot of time anyone had anything similar hopefully with a solution as I've spent several days on thsi already trying every suggestion I can come across/