PC is not properly booting after installing Avast

Hi all,
I have been using avast since last 2 years. Last week, i encountered two strange behaviours on my PC.

  1. Not booting properly. A black screen appears with mouse pointer. Only respond to Alt+Ctrl+Delete. And i need to presse external restart button of my PC to start properly.
  2. Its not waking from sleep. Instead, it shows the sign in screen but i can’t type my password into that text box, nor i can access on_screen_keyboard also. All i can do is pressing Alt+Ctrl+Delete. I can’t even select shutdown or restart from the power icon. If i do that, screen is blinking. But the PC will restart when i press the external restart button of my PC. Then i decided to format my PC. After formatting, i have installed avast and then these symptoms repeated. So i understood that avast is making problems. And then i formatted my PC again and this time i did not installed avast. I had used my PC for one week without any problems. Today i have installed Avast again because, i have 318 days licence left. But after installing the same problems (1 & 2) occurred again. What do i do ?
  • Which Avast…? (Free/Pro/IS/Premier)
  • Which version…?
  • OS…? (32/64 Bit…? - which SP/Build…?)
  • Other security related software installed…?

Hi,
Thanks for the reply.
Avast Internet Security Paid version.
Program version - 18.3.2333 (build 18.3.3860.316)

Windows 8 pro x86
Version - 6.2.9200 build 9200
4 GB Ram
Intel Pentium dual core processor 2.6 GHz (64 bit processor)

No other security softwares were installed.
Hope this will help.

Update your OS to W8.1 or W10 and try again.