Should I enable Firewall and AntiVirus on a VirtualPC VM? [duplicate]

You might want to have some antivirus protection depending on what you intend to use the VM for, Light usage you will probably be ok

If you are using the VM for a server however you should probably install antivirus and a software firewall.

Virtual machines are subject to many of the same vulnerabilities as operating systems installed on actual hardware. Secure each virtual machine as if it was a physical computer.

There is a discussion on the VM Ware forums about this issue you might want to read into. http://communities.vmware.com/thread/140056

Do I need anti-malware software and/or firewall on a VM?

Yes, most likely, you do. Unless the data in that VM is irrelevant.

Is my VM protected by the software on my host machine?

Most likely not. Depending on your virtual networking setup, it is possible that your host acts as a router for your virtual network. Then you wouldn't need an extra firewall for your VM (unless you need firewalling on an application-level).

Your hosts anti-virus software won't protect your VM.