Electronic Arts gave away free Command & Conquer Red Alert 1 yesterday and I immediately downloaded both Soviet and Allied CD at the size of 500MB each file. The Soviet CD downloaded fine in Firefox 3 but then when the Allied CD completed downloading, the download window just kept on showing that it is “Scanning for Viruses…”

I am aware of this new feature in Firefox 3 but it usually takes only a few seconds to scan for virus but this time it never stops! The file is 500MB in size and I am afraid that closing the Window will cause the file to be deleted and I had to download it again. Luckily manually closing the “Scanning for Viruses” window doesn’t corrupt the downloaded file. This feature doesn’t make much sense because if you have an antivirus installed, there should be a real-time protection automatically scanning the file once it gets into your computer and if you don’t have an antivirus, you don’t even need this feature at all!


Firefox knowledge base did say that in Firefox 3, if a Windows user has an antivirus program installed, it is launched to scan files when they finish downloading. Firefox 3 automatic scanning can be disabled by following the few simple steps below.

Open Firefox 3, type about:config at the URL bar and hit enter. You should see a screen warning you that “This might void your warranty! Changing these advanced settings can be harmful to the stability, security, and performance of this application. You should only continue if you are sure of what you are doing.” Click the “I’ll be careful, I promise” button.

Next, type browser.download.manager.scanWhenDone at the filter. You should see the preference name browser.download.manager.scanWhenDone with the status as default, type boolean and value as true. Simple double click on the value and it’ll change to false.

The effect is immediate without the need to restart the Firefox 3 browser. The next time you finished downloading a file in Firefox 3, it will no longer auto scan for viruses.

Just wondering, since Firefox 3 is able to automatically scan files with the installed antivirus, why isn’t it capable of detecting if the computer has an antivirus installed or not? If yes, antivirus will scan the downloaded file and if no, the auto scanning for viruses will be deactivated. Another thing that I’d suggest is they could add a configuration for this in options.

Related posts: