Windows 10 was telling me “Critical error: Start Menu and Cortana aren’t working” every few days, and the solutions recommended by Microsoft did nothing to fix it. After doing research elsewhere, I found that most tech forums seem to have reached a consensus that people with Avast tend to have the issue more than people without, so I uninstalled Avast 2 weeks ago and the issue has been gone ever since. So, has this issue been fixed yet? I can operate without antivirus, I have my web browser in Sandboxie, use Adblock Plus, and don’t visit any shady sites, but it makes me really uncomfortable doing so because you never know if Windows 10 will develop vulnerabilities that sandboxing the web browser won’t protect you from, like Windows XP had pre-SP1.
I couldn’t tell you whether this issue has been properly resolved, but another user here explained that this issue is a bug in Windows 10, and not Avast. He also provided a workaround. You can install Avast in Windows 10, and when this error crops up, simply restart in safe mode, login to your windows account, then restart windows normally.
Hope this helps.
The correct fix to this Microsoft problem was to boot into Safe Mode with Networking.
Once in Safe Mode, reboot to regular mode. Problem solved.
(The reason it also worked when using the Avast removal tool is because it boots you into Safe mode and than back into regular mode.)
I am about to get a new m/c with Win10 loaded.
Is this bug likely to manifest itself or have Microsoft fixed it? If not, would not loading Cortana (something I never expect to use) avoid the problem?
Regards,
ken
I haven’t heard of this problem on a system that came with Windows 10 pre-installed. 
No it has not been fixed as my computer exploded only but yesterday with that same critical error as mentioned. This was the first time it did so however I have only recently upgraded to WIN 10. After a long while of combing web on tablet I found and obscure entry regarding getting rid of avast to fix problem, therefore I had to uninstall it after many years of use. Win 10 immediately works again following Avasts removal. What happens now as to all my subscriptions :-\
Sadly , WIn 10 would nt allow a boot in safe more , just kept getting message " Critical error Start menu and Cortana nor working to sign out then back in and windows will try and fix the problem." Which obviously it never did hence the removal of avast totally. I also dont like not having my antivirus nor VPN software whilst being online however I am hesitant now to re install Avast if my PC & Win may explode once again.
Here are the instructions for starting your Windows 10 computer in safe mode, if you cannot gain access to your desktop:
- move the critical error window out of the way by dragging it
- Press ctrl-alt-del and choose Task manager
- In task manager, click “More details” at the bottom
- Click on File → Run new task…
- In the run dialog, type “msconfig” without the quotes. Place a check in the box provided, and click ok.
- in the system configuration window, click on the Boot tab
- Place a check in the box for Safe Boot, and change it’s radio button to Network, then click ok
- When prompted to restart, please do so.
Note: You do not have to undo this method in order to reboot in normal mode.
Thanks a alot for the help. I initially manged to un install avast and fixed problem only to re appear again a day later after re installing AVpremier. I will try to re “safe boot” as you have explained
At least 2 last Insider builds of Windows 10 do not show this bug. Hope the fix go also for normal builds of it.
I am still having this problem, last time was yesterday, 21 Oct.
I was very surprised to see so many different forums had the suggestion that removing Avast was the fix. I took my time and ignored those people long enough to find that rebooting in safe mode clears up the missing Start, but I am still not sure about the number of people stating that the problem never came back after they removed Avast.
It does look like coincidence and people imagining a correlation. Glad I found a more sensible solution, but hope the problem goes away soon.
The explanation is really very simple:
Using the Avast removal tool forces the system to reboot into Safe Mode to remove the parts of Avast that can’t be removed
while in regular mode.
That reboot into safe mode to clean up and finish the Avast removal also meets the fix for the actual Microsoft fix to the Microsoft problem.
So, are you saying the permanent fix is just to boot into safe mode WITHOUT uninstalling avast then boot into normal mode then it’s fixed forever?
I don’t get the critical error and I’ve turned off cortana, but I sometimes on start up, don’t get a start button and the icons on the task bar are squeezed together and program title bars aren’t correct. A simple restart fixes it, but the problem returns after a while.
It’s worked on any of the systems where this error has popped up. After a boot into Safe Mode with Networking and then a boot back into Regular mode, the error has never come back.
Ok, thanks, I’ll try it the next time I get the ‘phantom’ start button.
I’ve been running Windows 10 on a local account and I haven’t had the issue in a while. I used to get it all the time, but not anymore. What always fixed mine whenever it occured was just hard-booting the computer and booting it back up. Regular shutdowns didn’t fix anything.
You are not completely right. I had this issue with “critical error” many many times on W10 with Avast. After a few weeks I decided to clean reinstall W10 on my PC, installed Avast, 3-4 days passed and bam, critical error was here again. So I reinstalled W10 again, this time with another AV program (so NO safe mode reboot) and you know what? Errors are gone! I’m not saying that Avast is the cause of these issues, it rather looks like some other AV’s just behaves the way that prevents W10 to fall into erroneous state, like boot slowdown etc…
Unfortunately it isn’t fixed forever, it has happened several times now. At least I know the quick way to overcome whatever is screwed up now.