I use a software firewall for such issues, specifically an older version of Comodo. It allows me to deny access to the net for any specific program, at any specific range of address’s. For instance, let’s say that avast starts your browser, sending it to the chrome signup page, simply do a “nslookup” on the web address to find the IP, then a “whois” on that IP to find the entire range of IP’s. Now create a rule in your rule based firewall that says for this program, either avast or your browser, which ever is affected, to not allow an out going connection to either that single IP or the entire range. Now you never have to worry about that again. Of course always remember that if you use the entire range owned by a company, you shall never be capable of getting to other sites that may be hosted by, that company, say google, for instance. You can find “NSLOOKUP” and “WOIS” interfaces on the web, but I use an old version of Net Scan Tools Pro, that I bought way back in 2000, that’s still just as viable today!