For me, disabling the antivirus entirely wasn't necessary. I run Avast! too, and was able to get on fine after disabling the Web Shield only. For all those who don't know how to do this: To disable your Web Shield (for Avast, that is), open it, go to Real Time Shields on the left, click Web Shield, and hit Stop on the process. This should disable it and allow you to get on with Chrome or whatever browser you're having trouble with.