Avast on new Win8.1 64 bit is breaking all my downloads.

Avast Free Antivirus / Premium Security
1

Hi all,

Been using avast for a few years now with no issues. Last week I built a new PC, best of everything - i7-4790K, 32GB ram, 500GB Samsung SSD, etc with Windows 8.1 64 bit.

First weird thing was the Java JRE installer wouldn’t work… nomatter how many times I downloaded it it failed to run properly. Other downloads (of my normal environment) were also getting stuck at 99%. Then I wondered if the AV was causing issues so disabled it for 10 minutes and redownloaded Java. Perfect.

I also today noticed that my Steam games downloads/reinstall was stuck at 8.2GB for hours - turn off Avast and it resumes.

Final, wtf is going on, was in Virtualbox with Win8.1 64 bit and no antivirus installed. VLC (videolan.org) download was downloading but corrupted every time. Even getting different file sizes every time I downloaded it. None of them would run.

In my host, sure enough, disabling Avast lets the Guest VM complete the download properly.

Same with downloaded media files… all ok up to the last 5 or so percent, then nothing.

So I’m hoping Avast isn’t sitting in the middle of my IP connection - affecting everything in and out? Perhaps it is the File system layer when writing to the SSD. Either way, Avast is doing something very very wrong.

Ironic that I have to turn off download protection to actually download anything successfully.

2

Check if windows defender is disabled.
Check if the windows firewall is disabled.
What exact version of avast?

3

Thanks for the reply.

Windows Defender: Off
Windows Firewall: On
Avast Version: 2014.9.0.2021
Virus Def version: 140924-1

The above are default values on this fresh Win8.1 install - I have not changed anything.

4

What EXACT version of avast?
Free?
Pro?
IS?..

5

What firewall are you using ? Is avast allowed access through the firewall ?

6

Sorry - Avast Free.
Firewall is the default Microsoft Windows firewall There doesn’t appear to be an explicit entry in the firewall for Avast, but it is capable of downloading updates, connecting to my profile here, etc.

7

Since you mentioned a problem with Steam downloads, I’ve reported this to a Moderator.
Hopefully Avast will reply.

8

Thanks for the replies everyone, however, I can’t stand it anymore. Uninstalled Avast and installed AVG.

9

Sorry to necro this thread, but it describes exactly what’s been happening to me the past couple months I’ve had my new 64bit 8.1 laptop. Turning off avast allows downloads to complete successfully.

Mine is a vanilla 8.1 system, nothing exotic installed. Not holding out too much hope for this, but thought I’d give it a try having been a pretty longtime user of avast.

10
the past couple months I've had my new 64bit 8.1 laptop.
did your new laptop come with preinstalled AV from factory? was this removed before installing avast? did you remove it according to that vendor`s instructions and removal tool?
11

Yeah it did come with mcafee but it was removed via windows and their cleaner tool. It was probably the first thing I did on this computer and it was certainly before avast.

It’s really remarkable how well it screws things up… All browsers fail, even the adobe flash updater downloader fails unless avast is shut off.