From France - Can't uninstall CIS (W10)


We’re french so sorry for the mistakes.

My father had a problem because of a Windows 10 update and unexpected restart.
Since then, Comodo antivirus disapeared, he only has the firewall.
But he can’t uninstall it correctly to install it again, or activate Windows Defender meanwhile.

I tried several things : unistall with Windows of course, with the Comodo tool, with your new uninstall tool (it seems to uninstall but some things remains), with Revo uninstaller (it doesn’t detect anything), scandisk for Windows, Ccleaner, using the “without failure” Windows mode to do this things (don’t know how you say it in english sorry)…

And we still have Comodo keys, etc…, blocking uninstallation, Defender activation and probable for a new CIS installation.

We’ve read what you ask for bug reports, but it’s too difficult for us. My father doesn’t find some elements your ask for bug report.
I enjoin what my father could do and find…

It’s a pity because we’re very satisfied with CIS ! I also use it for my job.

Thanks if you have an idea to help us…

Hi harmonycom,
Team will get in touch with you by Monday to look into it.


OK thanks, have a good week-end :-TU

Hi, harmonycom.

Your issue is under investigation. Please check your PM.

Kind Regards,


Thank you, I transfer to my father (he doesn’t speak english at all) and I’ll let you konw.

Have a good day,

I answered by mail but I don’t know if you receive it, so I also post it here.

I didn’t find the indicated registry key.
So di you think we can now install CIS again ?

Have a good afternoon (here it’s 18H26 PM)

Hello, Sandra.

Please try to install again. If it is impossible, please try to check remains of CIS via new CIS uninstall tool. Are there any CIS remnants? Remnants should be absent in all strings (message “not found”). If there are some remnants use button ‘Clear’ and restart PC. Repeat these actions until remnants will be absent. If all strings will have messages “not found” then you are able to install CIS again. Please provide me results.

Kind Regards,


We could’nt install CIS again

The uninstall tool doesn’t find anything, file not found, as you said.
You’ll find enclosed the error message (1601). It seems to be because of Window Installer.

We bought the “pro” version this morning. We hope to be able to install it !

Thank you for your help.


Try running SFC /Scannow from an elevated command prompt. It seems like the Windows installer service is corrupted. Also try running this troubleshooter application from Microsoft.

The former given things didn’t work but Sergei helped us. It seems some register keys remains in our french version.

Many thanks for your help :-TU :-TU :-TU
You have now loyal french customers :slight_smile:


Kind Regards,