The answer is … No
- 2 will interfere with Windows
- 2 will cause your computer to slow down
- 2 will not keep you protected as 1 may negate the other one
- 2 may cause false results to be displayed – 1 may say that the other is an infection
So the answer is 1 and realise that it is your actions that will cause you to be infected and the antivirus solution will in most cases NOT save you.
So amongst other things:
- Keep your operating system up to date
- Keep your software up to date
- Stop clicking and opening emails that you know will
Realise that running as an administrator will override the antivirus causing infections to be installed