Try Safe Mode. Use their cleaner here: http://www.avast.com/uninstall-utility Then re-install.
this is an unpleasant issue 
We haven’t reproduced it in our environment yet (and haven’t met it during build testing unfortunately).
Could anybody send me your “setup.log” (or Support package) ? Not after un/re-install situation but from the time when the "webshield isn’t working (or log even after “remove” /add webshield would be helpful).
thank you
Lukas
Murphy strikes again! I copied my setup.log from boot time this morning until I got it working again. How do you want me to send it to you?
Unforunatly my dump file doesn’t seem to of saved, as i’ve restarted my pc since. I’ve just heard that re-installing the web shield fixes it, so i’m wondering, if i install it now (i used that uninstall tool to remove it properly) will it work without blue screening?
I have the same problem, I used the change feature to remove and after rebooting add WebShield, but it didn’t fix it.
Used “thekochs” 7 Steps, and works perfect…Web Shield is now working…
Thanks… ;D
[b]I have tried the suggestion and it did not work I have a Dell laptop Win 7 64 Home Premium Wondering if I should re install avast?
Ren
It happened to my new Dell too. Started off on 7.0.1473 last Sunday and only noticed there was an x today. Upgraded to .1474 but didn’t help. The change feature of removing and re adding web shield worked.
Bummer too as the unit isn’t even a week old and except for HP printer driver, nothing’s been installed except Avast and windows updates.
I got it to work followed the suggestion it didn’t work at first tried it again and it worked 
“thekochs” (above) worked, thanks.
This happened on the Win 7 machine, no trouble on the Vista machine, 32 bit build.
Anything else I tried, failed. This fix seems solid. And much easier then the other things I attempted, and learned from, in the process. Although, I cut my eye teeth on getting myself in trouble back in the day, just so I had something to fix. (learned to type on a Vic 20 punching code, that’s why there are so many edits to this post ;), they all looked good at the time.)
Avast!, I recommend your product for many reasons to others, this is a major screw up. This piece of an update has serious issues and I am very much surprised that such a thing was ever released.
I now know the F8 key won’t work on this machine and how to get into safe mode (and out) of 7.
Win some, loose some, hey? Tech boys going to make money off this screw up, I do think.
thekochs fix didn’t work for me at first, I tried it again and it did. The thing that worries me though is that it was working just fine after The update, it wasn’t until just now it decided to pull this, which leads me to believe it could happen again if the issue isn’t found and fixed soon.
Sounds like behavior I was seeing after the uninstall/reinstall stuff that didn’t really work. I would work, then would partial work, the fully wouldn’t work and…well I didn’t want to track ti any further to see if there was a pateran…this has not failed yet and I did it for a while. However, keep us informed, please.
The re-install (uninstall and install) of web shield didn’t work for me.
Hopefully Avast can resolve this soon.
Right, it did not, use “thekochs” method.
I am guessing more then a couple of these other problem posts are dealing with what I saw happen in the process of trying other things, as well as just noticing the “problem” in various stages for the first time.
Try the above, for now. Just do it as he says, even if you don’t think it is the current issue.
Hopefully Avast can resolve this soon
I had the same problem, no web shield.
Also i was in the last 7 days before re-registration, attempting to do the registration just hung the interface.
Removing web shield and putting back didn’t fix it.
The only thing that has working is a complete uninstall with aswclear, and a full re-install.
Hello .
I had the same prob in IS .
My system running in windows 8 x64 .
Yesterday i try repair ( from add/remove prog in control panel ) but not work.
After i unistall IS and install again .
Problem fixed .
Today open again my pc and had the same problem .
Until this update never have any problem
Any help please ?
http://s16.postimage.org/6pmfu85lx/Snap4.jpg
Same problem here. I done a clean install of Windows 7 Ultimate. Within 24 hours the real time sheild was not active. No response from the fix it now button, or by enabling the sheild. Resorted to a complete reinstall of Avast. That fixed it for 36 hours. Turned machine on this morning to find that the real time sheild was once again turned off, and again, no luck at all at turning it back on. This time i will try the method mentioned earlier - the change option in windows control panel. If not, another reinstall will be performed (second within 2 days!).
Problem is, this is not one of my machines, it belongs to someone that is not that good with computers, so i am worried this is going to occur again within a few days. The owner is not going to be too happy to find a problem like this so soon after getting his machine back from me.
Any thoughts or input from an Avast member? Are you guys working on a fix for this seemingly common issue? Do you acknowledge it is a problem?
I had same issue on windows 7 ,i tried all other solutions.But after reboot issue was here again so i stopped windows defender and started it again andnow it is working fine. DETAILS : go to Control Panel ->System and security → Administrative tools click on SERVICES ,find WINDOWS DEFENDER and Stop the service and start it
Thanks for post.
My windows Defender has been set to manual for many years, yet still had the Web shield problems.