Fixed for me.
Avast support came through with a solution. I am super impressed with Avast because I am only using the free version, although my company pays for the Pro and Linux Server versions at work so I don't feel too guilty.
The step that did the trick for me was to download and run Ccleaner from
www.piriform.com, and run registry cleaner. After that my internet speeds were back up with Web Shield turned on. Whoever at Microsoft thought up the whole Registry idea should be given a special place in hell, although hell might be too good for them.
If that does not work, here is my summary of things they suggested. I did all of these too, so if the above did not fix it I would try all of these. Also I noticed it can take a few minutes for Avast Web Shield to activate/deactivate, which can make testing a bit ugly. If you go into into Avast/Statistics you can see if the shield is checking the download files.
First:
- uninstall any other antivirus software, or at least turn them off
- ensure you have the latest version of Avast
- reboot
- uninstall Avast (and ensure the avast program directories are empty) and then do full clean reinstall
Then:
1) Run a boot-time scan (Avast>Security>Antivirus>Scan Now)
2) Download and run Ccleaner from
www.piriform.com, and run registry cleaner
3) Consider running a shot of malwarebytes and then uninstall it.
4) Make a browser cleanup from inside Avast (Browser Cleanup Tool).
As I did all of these it might be a combination of things, but the registry clean was what did it for me.