Block ping request and Nmap scan


I am learning nmap scanning from beginning.

I tried to scan my office pc with the following command

nmap -sP -PP 192.168.1.104 --disable-arp-ping 

and it works fine..It shows that 1 host is up

BUT

when I tried to scan for open ports then it shows errors.

I have used all commands like nmap -f, nmap -sI etc but I can’t scan the host.

Actually my target pc is using Symantec antivirus and he is blocking my IP address because when I used to ping then it shows nothing.