Adding anti virus to Win 10

[Janis]

I want to install Kaspersky anti virus on the pc.  Do I need to delete Microsoft first?

[ngc2392]

no, it will disable itself. The firewall option will remain though: Unless you are having kaspersky internet security.

[Hind24P]

Yes, you can go ahead and install Kaspersky, there's nothing to remove first.
Make sure to check, though, whether you don't already have an antivirus program, even a trial version, like McAfee or Avast.