Depends what you mean by 'block' You can use the Fiddler 'Filter' tab to include/exclude specific URLS (e.g. 'Hide the following hosts' , 'Show only the following hosts' etc) but that is only excluding info on those hits from the Fiddler display - I don't think Fiddlers meant to act as a firewall and actually block HTTP traffic

>After my son used my computer for a bit, I saw a whole bunch of ads websites. Do you know if there is a way to block them from Fiddler?
>
>>>I see several URLs like this in red
>>>
>>>http://www.levelextreme.com/.wav
>>>
>>>Why is it so?
>>
>>If it's in red it denotes a warning or error message from the URLs server. The 'Result' column is the HTML result code.
>>The only one I see for the UT main page (www.levelextreme.com) is a 404 error when looking for a file named '.wav' (That looks like a coding problem on Michel's part to me since thats not a valid path or filename)
>>BTW, if you look at the 'TextView' section on the bottom rigfht of Fiddler you will see the full HTML returned by the server.
>>
>>FWIW I don't see how the choice of browser would make any difference in this instance - Neil should see the same error in IE......
>>
>>>
>>>Thanks in advance.
>>>
>>>In addition, I see several links like this
>>>
>>>http://safebrowsing.clients.google.com/safebrowsing/downloads?client=googlechrome&appver=10.0.612.3&pver=2.2&wrkey=AKEgNit4zIHTfI8dzfjM_Yeichc9no1uYstAil4QcOoibuNz-lNBldT0SLabmgX-7t_Uup70uym-lB7dPB8nmq7dsDU3U6L9GA==
>>>
>>>What is it?
>>>
>>>BTW, I closed most of my GC windows and left only one with a few tabs opened.