Hi,
It is working now fine ... I had forgotten to remove McAfee which were originally installed .. Thanks guys !
- First uninstall Avast via add/remove.
- Download and run Avast Uninstall Utility in normal mode and it will ask you if you want this tool to run windows in safe mode automatically. Click yes and this tool will run your computer automatically in safe mode.
- Uninstall Mcafee via add/remove and follow instruction. Download the McAfee removal tool via here
http://mcafee-removal-tool.com/ and run your computer manually in safe mode and run that tool.
- Download and install a fresh new copy of Avast (make sure you un-check any optional software that is being offered i.e. google chrome, google drive, and etc) and click on custom install so you can choose which feature you want to have and don't want to have. After it has been installed it will do a quick start up scan. Once that is finished restart your computer manually again and register your copy of Avast Free.