How to block URL in avast 5

hey, can i know how to block URL in Avast 5 free antivirus?

In version 5, it’s only in paid products. But it will be free in version 6, which is already in beta. You can give it a try, but make sure you use it on a test machine and not a work machine.

You should be able to do that in any competent firewall or in the HOSTS file or by using a HOSTS file manager. Or many browsers also have blocking tools.

See:
Blocking Unwanted Parasites with a Hosts File
http://www.mvps.org/winhelp2002/hosts.htm

A good HOSTS file manager is HostsMan.

+1 Best software for Unwanted Parasites