Avast Web shield FAIL help!

Hi! So I’ve updated to the last version of Avast, and after the reboot my web shield is down and won’t come back up. I run Windows Vista 32 bit. I’ve tried to turn it on in all possible ways, the ‘enable all shields’ option in the taskbar, I clicked the ‘turn on’ button in the UI main page, I went to the settings and tried to turn it on individually from there but nothing.
Does anybody know a way to fix this?
Thank you in advance

Controlpanel > ad / remove programs > avast > uninstall / change > repair option

I should have mentioned that I’ve already repaired it with zero results. And I removed it entirely and reinstalled it. Still nothing.

I figured it out: I just needed to install AVG instead! Thanks for nothing though

SAME thing here, web shield will allow itself to be turned on but then turns itself off right away. CAN NOT find a way to fix it.

Vista 32 bit, latest Firefox (40). All else is working fine.

is any previous used AV removed according to vendors instructions using removal tool?

General: Uninstalling a third-party antivirus software https://www.avast.com/faq.php?article=AVKB11#artTitle