system
41
If that helps to someone, this is the way I solved the problem (Windows Vista Home Premium SP2):
- Uninstall Avast using Control Panel features.
- Reboot sysyem
- Dowload avastclear.exe from Avast web to desktop
- Reboot system in secure mode (pressing F8)
- Execute avastclear.exe from desktop
- Reboot
- Delete “AVAST Software” directory (even if it was empty).
- Download Avast Free Antivirus from Avast web
May be it were enough 1,2,8 or 3,4,5,6,8 or … but …!
Have a good luck and thanks a lot for all of you!
My computer is running Vista x64
system
43
My computer is running Windows 8.1 64bits and had exactly same problem, hope they will fix it soon…
system
44
try disable the behavior shield
system
45
I just wanted to chime in. I’m running Win 7 64bit SP1 with the latest updates, and noticed the slide out notification saying avast needed to reboot due to an update.
Uh, I had updates set to manual TYVM.
And of course, upon updating and logging in, I was met with a solid color background with only my mouse cursor, I couldn’t even ctrl alt del.
So after waiting about 15 mins, I had to do a hard reboot. I could get into windows, but avast kept complaining it couldn’t load the GUI now and then, and that the AV service had stopped.
SO I repaired…and it kept saying I needed to restart.
I restarted THREE TIMES, and it kept saying the same thing in the main program window.
So I did the uninstall/clear/install, and now it seems ok.
Seriously guys, I have had issues with new versions before, that’s why I usually wait awhile before installing, to see if anyone else has problems.
I don’t appreciate the headache and wasted time/
And I also don’t appreciate popups for your other products AFTER I’VE PAID FOR ONE OF THEM.
system
46
Hi everyone, I’m running Windows 7 Home Prem SP1 up to date. I’m having the same/similar problems with this new version. Tried all of the recommended approaches and none of them worked. Luckily I make an incremental backup before making any changes to my system , so I finally went back to the prior version.
I’,m also under the impression that a clean up tool that implies that it will remove Avast from your system, should do exactly that. If it does not then it should be spelled out in the write up for that tool. Just for the record, I use a program to monitor every program installation and after using that to do a “clean” uninstall, and then an offline full install, same results (blank white screen, numerous error popups and on and on and on again. For now I’ll stay with the previous version.
If you have Windows Defender, it shuts down when there is another similar program installed, but the minute that I rebooted after making a complete uninstall of Avast, Defender came alive again, alerted me that updates were available. So I’m fairly certain that Avast was removed completely
Sure hope they fix this problem
system
47
Happy to report that unchecking the behavior box solved the problem. I rather liked the spear icon though. But what a relief every thing is back to “normal”. There a couple of pinned icons that had to be reinstated. Very Happy camper ;D
system
48
This update is seriously flawed. Go to safe mode and revert to a previous start-up that worked.
Wait a couple of month to try the update again to give AVAST an opportunity repair this flawed update 17.1.2286.
Audpeto
system
49
Hi all，
This problem happens on Win 10 Pro latest version, too. I use repair install(from control pannel) and can fix it temporarily. But few days later, the problem happens again when I open Avast.
system
50
I have VISTA HOME Premium. All was OK until I did an Update (at the the AVAST programs request) on Feb 10th 2017. User Interface now not working for me. Did a repair, repeated updates to no avail. As well, my license for AVAST Internet Security has gone astray in my AVAST account. Also if I click on any license file my computer tells me its corrupted. Just repaid for a year in Dec 2016. My AVAST firewall is working.
system
51
I just ran into the same issue out of the blue. Have been using the latest version for days without any trouble, then this happened. (I did make a clean install using avastclear.exe, so…)
That’s not an acceptable solution, by the way.
Asyn
52
I have tried the beta versions where the issue started poping up and decided to go back to using the current stable one and it only runs once with the current UI, that’s right after the installation and a restart can cause the UI to not load up.
Rendering the product useless in my system, I have tried to make it work multiple times but failed to get it to work in any form.
Forced to use another product now. I hope they fix this issue and get back the functionality of the stable product.
It sounds like lot of people are having trouble with the same issue in an around.
Asyn
54
Will test that up and see if it resolves the issue. 
Since you’re having a problem, I would suggest that you do a :
Clean Install of Avast:
https://goo.gl/4Ptzkf
I am doing clean installation of Avast! Using the uninstall utility to remove it via safe mode then getting back in and installing the product. Well any way, getting back to the issue. It is not yet resolved! It came right back up after the restart after installation. 
Too bad avast! too bad…
https://image.ibb.co/ma415a/avast.png
What operating System ??? 32 or 64 bit ???
Which Avast product ??? (Free or paid)
Other security software installed.
system
59
The Behavior Shield seems to be the problem. If you disable it, all returns to normal. But this is less than satisfactory since it reduces protection. I’ve reported this issue to Avast (so far no response), so hopefully they will issue a fix. otherwise, it will be time for a new product.
I’m currently trying this: add C:\Windows\explorer.exe and C:\Windows\ImmersiveControlPanel\SystemSettings.exe to Behavior Shield exclusions. I don’t know if it will work, but it’s worth a try.
Behavior Shield is active on my system without any problems.
That’s why I asked the question that I posed in my last reply.
