The reason I mentioned another AV is that most new systems come with one pre installed ?
Another thought is that in Win8.1 windows defender is effectively a full AV (Microsoft Security Essentials), this however, should be disabled by the OS when you install a third party AV like avast. You could check and ensure windows defender is in fact disabled.
It is a bit strange that this is only going on on one of the systems though, presumably these are all the same sort of installed applications, etc.
EDIT: if you check in the task manager is avast actually running (avastSvc.exe) and just the avastUI.exe (avast user interface, tray icon) not running ?
Outside of this I’m a little short on other suggestions as I don’t use win8.1.
The one good thing is that the avastSvc.exe is running that is the main avast service/process and handles all of the scanning/shields, etc. The avastUI.exe it the user interface providing access to the user interface and settings, it doesn’t have a security function.
What happens if you double click on the C:\Program Files\AVAST Software\Avast\AvastUI.exe file ?
Since this is a User based function (not System), something may be blocking it, which may become apparent when you try to run it.
Hi all,
Thank you very much for your support.
The problem is fixed! ;D
I have found another topic with the same problem and an hint to Microsoft One Drive, formally known as SkyDrive.
Unfortunately I had forgotten that the PC with the Problem uses an Online-Microsoft User Account. That’s the difference to the other PC’s.
I deactivated the start of OneDrive by using gpedit.msc
… and after rebooting the system the avast icon was in the tray.
Glad to hear that your problem is solved.
Your explanation however doesn’t make any sense to me.
I run both Onedrive and Avast. Both are functioning without problems and,
the Avast icon is in my system tray.
What does Onedrive have to do with the prevention of the Avast system tray icon ???
I agree with Bob, that is certainly strange as I can’t imagine any association with Microsoft One Drive and the avastUI function. There just be some coincidence along the way, you could try enabling it again and see if the interaction/conflict occurs again.
You mentioned:
I had forgotten that the PC with the Problem uses an Online-Microsoft User Account. That's the difference to the other PC's.
If this truly has its own USER account, I just wonder if at the time your USER Account is trying to run the avastUI.exe it is connecting to OneDrive using its USER. If this is the case you could probably delay the start up for OneDrive so it doesn’t conflict with avastUI.exe starting.