after installing free, internet wont work

[REDACTED]

After installing avast free, now I'm connected to the internet but won't let me get online.
I tried IE and Mozilla but all I get is no connection. Google desktop won't load and system restore fails.
What happened and do I fix it. Avast free what caused it.

[Pondus]

After installing avast free..........   

Did you remove your previous used AV before installing avast?
Did you remove it according to that vendors instructions using removal tool?

General: Uninstalling a third-party antivirus software    https://www.avast.com/en-eu/faq.php?article=AVKB11#artTitle

[bob3160]

Are you allowing Avast access through your firewall

[DavidR]

The most common cause of losing internet connection after installation of avast free - is a security program blocking avast - typically this is your firewall.

What is your operating system and firewall ?
Does it allow avastSvc.exe internet access ?
- If it does delete the entry for it and reconnect to the internet, this should force the firewall to ask permission again.