No, it is not compulsory or requirement for Windows 7. But, it is extremely recommended to have these software. Firewalls and Antivirus will help your operating system (or sometimes, the whole computer) to be free from virus. They will maintain your computer to it's best state if used properly with antivirus and firewalls.
I would say it's quite opposite. Nowadays you must have anti-virus software on your computer regardless whether you have firewall or not.
Of many popular antivirus and firewall software, Windows 8 ranked fifth.
Most likely it is because your antivirus software has a firewall withch is blocking it, or the built in windows firewall is blocking it
Most newer laptops come with an antivirus program installed standard. My laptop (a Dell Studio 17 running Windows 7) came with Windows Defender/ Windows Firewall and McAfee antivirus.
According to Norton, Norton antivirus does not conflict with my windows firewall.
You can get it if you do not have the latest antivirus software and your windows software is out of date.
No. That you have to get seperately
There are many companies that provide free antivirus software downloads. Avast, AVG, Avira, and McAfee are a few examples of who provide the free software.
Open the relevant ports on Xp firewall
The best way to protect computer or network protected against worms is by regularly updating updates for windows and antivirus, also by using hardware in network.
Great firewall software would include zonealarm or webroot. Even the windows firewall included with Windows XP SP2 and beyond should do the trick. And remember that if you have a router it also has a hardware firewall in it.
There are no hardware firewalls built into Windows 7, but from Windows 7 and on, Windows Defender is integrated into the system.
Windows Defender is a software which is from Microsoft. Specifically, it is anti-spyware software, which protects your computer from spyware and malware infections. In Windows 8, Windows Defender has been upgraded to an antivirus.