Can't donwload anything with Avast up

Hello,

I use Avast for many years now, without issues. So of course, when yesterday I received my new computer running Windows 8, I removed the pre-installed AVG to install Avast. But then, all my downloads failed.

Some of them never finish the download (blocked at 99%) like http://download.virtualbox.org/virtualbox/4.3.20/Oracle_VM_VirtualBox_Extension_Pack-4.3.20-96996.vbox-extpack
Some other ones when I click on the link I have a windows message “This file cannot be saved because the source cannot be read”.like https://dl.bintray.com/mitchellh/vagrant/vagrant_1.6.5.msi

If I try to send same files from my old computer, all is good (same Avast version, same parameters, but windows 7).

If I deactivate Web Agent in Avast Active Protection, then I can download anything.

Do you know how to beneficiate of the same protection as my old computer where I do not have any problem?

Did you use a avg removal tool?
http://www.ache.nl/index.php?location=mal-01

If not please do so and after that perform a clean installation of avast.

Hi, I did. I removed Avast, rebooted, then run avg uninstaller, then reboot, then install avast.

Problem is the same.