Hi Craig,

Thanks for your input,

I tried a couple of reboots but the problem didn’t resolve itself. In fact, Internet Explorer locked up once more so I ran System Restore. After that, Avast immediately stated an update was required and I clicked the button for this to take place. After rebooting, I find Firefox is behaving as reported after the Beta installation. I am leaving Avast Online Safety disabled in Internet Explorer for the time being. I’ll watch this forum but, for the time being at least, I think I will leave things as they are.

Cheers for now.