If I were you, I'd mix and match the best
1)Get a genuine win 8.1/7 and keep it updated at all times
2)Get Kaspersky Antivirus or Bitdefender Antivirus
3)Comodo firewall (the best software firewall)
4)If you have a router, configure it for security,
even though software firewalls are quite great in synthetic tests, they'd actually be ineffective against real world threats
the only thing then which matters more than the rest is your router. Configure it so that it acts as your Hardware firewall.
5)Make backups of your PC , I'd recommend Paragon Hard Disk Manager suite/Professional