system
1
After installing the brand new version of Windows 10 on my machine (clean install), Avast is completely blocked from exiting passive mode by Windows Defender Security Center. Even restarting the computer like Avast asks me to, doesn’t change anything. In order to bypass this, I had to disable Windows Defender, enable Avast (Free btw) in the control panel and then turn off the Passive mode by going into the AV settings and flipping the little switch. After doing this, everything seems to go back to normal with all the components working like they should. The only down side (which honestly isn’t such a big deal) is WDSC not being able to tell the state of Avast Free Antivirus.
system
2
Everytime that Windows 10 has a major update (like the Anniversary, or Creators Update), I always fully reinstall Avast to prevent any problems.
Here I also installed the Fall Creators update yesterday, and Avast was acting a little strange, so I decided to fully reinstall it and now it’s working perfectly.
If your installation starts to act a little strange, I would reccomend to reinstall it too.
system
3
Like I said, I did a clean install of Windows 10, which means I had to do a clean install of Avast too. I actually tried reinstalling it 3 times, with same thing happening with every try. This just goes to show that there is an incompatibility between the new build and the current version of Avast.
I did a clean install of Windows 10 Creators Fall update today and am running Avast IS without any issues
system
5
Well, for me and for Alikhan, the program it’s working normally.
I may not work for Avast, but why don’t you post your computer specs here?
Maybe they will know how to fix the issue that happens in your hardware.
system
6
The machine in question is Lenovo MJ80. Also, right now I’m upgrading my other machine as well, I’ll keep you posted if the problem still persists. 
system
7
Maybe just some users are affected by this ¯_(ツ)_/¯
Hi q2460051, could you please let us know what is the language mutation of the operating system where the problem occured? Also, is there the “c:\ProgramData\AVAST Software\Persistent Data\Avast\Logs\Setup.log” available for further analysis? Can you please zip it and send it to me over email for analysis? Thank you!
system
9
All I can say is that the OS language is Serbian. As for the file, I can’t send it to you because I no longer have the machine. Sorry. 
bob3160
10
I just finished updating 4 systems to the latest release of Windows 10 (1709)
On all 4 systems, I opted before I started the update, to pause Avast’s shields till the system rebooted.
No problem on all these systems. 2 fairly new 64 bit. 1 very old 64 bit and one old 32 bit laptop.
DavidR
11
I only had one system to update. Given how long the Fall Creators Update took (plus previous Creators and Anniversary updates), there is no way I would disable avast for that long whilst being on-line.
system
12
And that’s why I keep the shield on, but after the update I always reinstall Avast to prevent any problems.
I know that I just have one computer to update (it would be really boring to reinstall Avast in 4 computers after every big update);
bob3160
13
I don’t have to re-install anything. Once the computer restarts, Avast is again totally active.
I’m also not downloading or installing from unknown sources.
I had the same issue, clean install of W10 fall creators update. It seems that Avast just do not turn off Windows Defender and instead stays in passive mode by default with a working Defender. It took me some time to solve this the same way you did.
bob3160
15
Was Avast active when you did your upgrade to the Fall Creators 1709 version ???
I turned the Avast Shields off prior to starting the upgrade and had no problems after the upgrade completed.
I did not do upgrade, i made clean installation of windows. The problem is that Avast do not turn off Windows Defender itself and instead working with it in passive mode. And you need to do some steps to turn off Defender and make Avast active AV as it should be. Actually it is not THAT problem but stll annoying. I saw some people on non-english forum with the same issue.
DavidR
17
It isn’t Avast that should turn off Windows Defender, when you install a 3rd party AV ‘Windows’ is meant to disable Windows Defender.
There have been issues in the past if you updated windows, it disabled the 3rd party AV (not just Avast) and enabled Windows Defender. This could result in Avast seeing WD is running and enter passive mode.
That said there was also a reported issue of Avast detecting what it considered you had another AV installed (or possibly remnants), resulting in Avast entering passive mode and a problem getting it active. I believe this detection of other AVs and entering passive mode incorrectly is a bug which I believe is meant to be resolved in a later update (or possibly the current beta).
bob3160
18
system
19
He said it was “Clean install”, perhaps he means that he did not upgrade from 1703 but he downloaded the entire windows 10 1709 image and install it in a clean drive.
There are updates in Windows Defender specially with firewall.
I had no problem getting the Fall Creators Update. I didn’t get it via windows update.
