I had used Malwarebytes to deal with a problem with Offers4U adware. That finally went away, but Malwarebytes seemed to be mucking with the browsers preventing them from working. So I removed Malwarebytes from my system.
Then the browsers were still mucked up, but I found a way to fix Firefox. Chrome is still mucked. The symptom is that immediately on rebooting Win 8, Chrome is running and can't be stopped with Task Manager. Trying to run another copy doesn't work, it complains that it is already running. Every web page I've found about this problem starts off telling you to use Task Manager to kill Chrome or worse, to run Chrome and kill off the other task with Chrome's task manager. Obviously neither work for me.
There are a few pages that recommend starting in safe mode and uninstalling Chrome. I hate to do that because of loosing passwords, history etc. Anyone have another idea? AVS doesn't find a problem.