Avast slowing my computer to a crawl

Avast Free Antivirus / Premium Security
1

I installed Avast today on a newish laptop. I haven’t used Avast on any computer in a while because last time I did, I had a very similar issue.

My internet connection is 150down/10up, Mbps. Before installing Avast my browsing was lightning fast, as expected.

The second I installed Avast, that changed. Websites that were loading in a blink before are now taking upwards of minutes to load. The ONLY thing that changed was disabling Windows Defender and installing Avast. (Only disabled for Defender because in Win8.1 it is built-in and cannot be removed)

I tried disabling the web shield, but it didn’t change anything noticeably. Is there some setting I’m missing? I vaguely remember a similar issue being why I uninstalled Avast from my Vista and Win7 computers as well. Everything is up to date, what can I do to fix it?

Note: Even the Avast site, I had to refresh this page twice in order for it to fully load in order to post.

2

Could you disable the Avast security addon in IE (and other browsers) to see if that makes a difference

3

Same problem. IE slowed to a crawl. Websites don’t load. disabled the extension as suggested…did not help any. Using Google Chrome works fine.

4

Did you remove any previous used AV or factory installed AV before installing avast?
Did you run that vendors uninstall tool to clear any leftover files that may conflict?

5

OK went into uninstall and did a repair on the Avast installation. That fixed the problem!