The result of that scan is negative also. As far as I am concerned, I believe your system to be clean.
Let me just tell you about your so-called error in Hotmail, ad.au.doubleclick.net. This address is known to many as an adware site, and something on your PC is protecting you from it. It is possible that you have installed MVPS Hosts or you have that name added to another form of protection.
I eill leave this thread open for a few days in case of misfortune.