Can't delete locked com.kaspersky.kav.sysext.systemextension

[Sister Sabina]

My 2019 Macbook Pro burnt out the other day and I had to get another drive. Fortunately, I had a time machine backup to restore from.  However, that hasn't gone as I had hoped.  Finally got my Apple ID but Microsoft Outlook crashes on loading.  I googled and found that Kaspersky and a VPN I had installed could be the problem.  I exited the latter and tried to uninstall Kaspersky Internet Security to no avail.   I have a zerob file (locked) in the Application folder.  Can anybody suggest how I can unlock this thing in order to trash it and if there is anything else that I am missing in not being able to access Microsoft Outlook?

 

Thanking you in advance

Sabina

Tokyo, Japan