I have just installed Avast free on my new computer and Webrep works on Firefox and IE, but not Google Chrome. It says it is installed for Chrome from within Avast, but doesn't show up as an extension in Chrome itself. I've searched the forums, tried uninstalling the Chrome webrep utility from within Avast, tried reinstalling, and it hasn't worked. In fact, everything I've tried hasn't worked.
If it helps, I'm on Windows 7 Home Premium 64 bit.