I use three chromium browsers in recently bought win 10 desktop viz Chrome, Slimjet and Avast "Secure Browser" (for its Bank mode). All have stopped working for no reason , this also happened few weeks ago and I had to do a windows restore . Updating, uninstalling & reinstalling them has no effect.Yet Firefox works and downloaded Palemoon (Firefox offshoot) and also works fine. Tried using System File Checker with no success . Totally baffled and any help appreciated.