@Roy1961
You may well have a nasty lurking there.
Uninstall Avast & reboot
Download & install Malwarebytes from here:
https://www.malwarebytes.org/mwb-download/
Allow Malwarebytes to update itself & then run a scan
Let Malwarebytes zap anything it finds & reboot
Download Adwcleaner from here:
Downloading AdwCleaner
Click the scan button to start
Once the scan has finished, click the Clean button & then accept the reboot
Uninstall Malwarebytes & reboot
Purchase, download & install Webroot Secure Anywhere anti-virus:
Fastest PC & Mac Virus Protection - SecureAnywhere Antivirus 2014 | Webroot
(Do not allow Webroot to load their add-on into your browser - which it will attempt on first browser run after installation of Webroot)
Done.
