1. Both Windows and Linux operating systems have good firewalls and security features, but Linux is often considered to be more secure due to its open-source nature and the fact that it is less prone to viruses and malware.

2. Yes, a properly configured firewall can add more security to crypto software wallets on a PC. It helps prevent unauthorized access to sensitive information stored on the device.

3. To add more protection to a Linux operating system, you can implement the following measures:

• Keep the system and software up to date
  

• Use strong passwords
  

• Enable full disk encryption
  

• Use a Virtual Private Network (VPN) for secure internet connections
  

• Limit user privileges
  

• Install security software like antivirus and intrusion detection systems.