Avast 2015 Freezing computer

[system]

Hi,

I am using Avast 2015, with OS Windows 8.1, ever it locking all internet activity. after restart the system it working fine.

active protection shield are on, file system, mail, web, secure Dns firewall, sometime it start work after off web, and secure DNS shield but some time it won’t

Thanks
Biswajit

[Pondus]

do you have any other security programs installed?

is previous used or factory installed AV removed according to vendors instructions / removal tools

[system]

No there is no other security program installed on it, recently I format my system and installed fresh copy of Avast 2015