I recent changed my antivirus from kaspersky to avast. Lucky I tried the free month with avast. 3 days later avast crashed my sistem with a warning from windows 10 that says that cortana and task manager has stop working.
I check out in internet and found that a lot of people using avast are having the same issue. So I unistall avast and huala! no more crashes from windows 10.
DONT INSTALL AVAST!
Crapy antivirus
Is there any particular reason why you registered with this forum just to criticize a security program you are no longer using.?
Why all the drama.?
Why even post at all.
Its more a windows 10 issue,
Diego,
did you removed Kaspersky completely before installing avast ?
If not, it can the cause of the problem.
What exact version of avast did you install ?
Cortana?
The idea is nice, but it has never worked as it should and still doesn’t.
If you want software that is really bugged, get Cortana.
I have been using Avast for years, and have been running it problem free on my windows 10 laptop for months. Windows 10 is probably crashing because windows 10 is junk. I don’t have windows 10 on my desktop pc yet because even after all this time it doesn’t work with my Nvidia GPU without crashing every 3 minutes.
Maybe you need to contact Nvidia and ask them why they aren’t updating the driver ???
Clearly not a Windows 10 problem. Please put the blame where it belongs. 
I’m with Eddy and Bob. It doesn’t appear to be an avast issue.
Uninstall Kaspersky using their removal tool then re-install avast.
Make sure all of your drivers are up-to-date.
For a list of removal tools see https://www.avast.com/faq.php?article=AVKB11#artTitle
@ Arnold Please refrain from being rude to users seeking assistance.
Please try to get more information or read/listen to what the poster is wanting.
We are here to help not to insult.
It’s not an Nvidia problem either, unless you’re using prior to the 400 series graphics cards then they’re not listed as Win10 compatible.
With all due respect but the OP has made it clear he no longer wishes to use avast
And that makes it alright to be rude ???
Of course not my dearest bob…you fight fire with fire and all that jazz.
It’s much more prudent to add nothing when you have nothing good to add.
Just stating the obvious. 
You influence more people by being respectful and polite.
You push people away by being rude.
Just stating the obvious.
Incorrect,
You influence people by being honest and truthful without contempt or deceit.
No. We need both things: (respectful and polite) + (honest and truthful).
Only being “honest and truthful” won’t be good here in forums.
Always, be “respectful and polite” AND “honest and truthful”
I took my time posting this because I almost put money in it. This is just a warning shot, if you still like to use avast its ok, not my problem. I did all the other things posted here, like unistall kasperky correctly (with their own unistall) and made a clean install of avast.
I am not a computer expert, but I know a few things.
This problem just looks like its just a compatibility problem rather than a “serius” problem, but for me thats enought to just dont buy the product.
Soooo good luck everyone.
I’m out
Avast works perfectly fine with Win10, possibly there is a compatibility problem With Win10 and your system or another security program which interferes with Avast functioning correctly, only way to know for sure would be to run off some logs to view what is happening on that system.
I phoned support and was told that phone support could not deal with my problem but that I could write to technical support and get a response within 24 hours. That was several days ago. I have received no reply and when I try to follow the link offered me several days ago get also nowhere (https://support.avast.com/helpdesk/tickets/69692). I am frustrated and will continue to look for venues to seek help. A description of my technical problem follows.
I bought a used computer on which was installed Avast and Windows 7. I uninstalled Avast by downloading the uninstall program from the Avast web site. I upgraded to Windows 10. Now I get a pop-up window approximately every hour announcing an Avast utility that wants me to upgrade Avast for Windows 10. Did your uninstall utility leave some registry with Avast information on it that leads Windows 10 to allow this Avast pop up window. How please can I remove the registry information your uninstall left behind, or if the registry diagnosis is wrong, then how else might I stop this pop-up? While Windows 10 is complicit in the problem, Avast evidently left information on my computer after the uninstall such that Windows believes I want Avast. While your product is highly recommended, I don’t want it on my computer, and might you please help me stop the pop-up windows telling me to update Avast.
(I tried to find a topic on uninstall or popup that was active or to create a new topic but was unsuccessful. I have a Ph.D. in computer science and have been a professor of computer science for 40 years)
royrada,
please start your own thread.
Then solving this should be kids stuff for you, we are just self learned normal users