Avast 4.8 can't connect to server, error message

Running Vista and Avast 4.8 when I try to update, I get an error message, “cannot connect to server” Tried with firewall off and still no go. I’m using AOL, on Broadband.

Which is the firewall?
Is avast.setup allowed to connect?
Was avast updating some days ago?

I was able to install and run avast, but it was never allowed to connect for update

Also…
Which is your operational system?
Did you have any other antivirus installed in this machine in the past? How did you remove it?

My operating system is Windows Vista.
I removed previous antivirus by going to Programs and Features.

I suppose you’re using Windows Vista firewall… am I wrong?

With Norton, McAfee, sometimes Kaspersky… this is not enough.
You need to download and use specialized tools to remove remains of these suites.