Virus over Home Internet Connection

I have just a simple Virus question.

A friend of mine might have a virus. Can the virus get to other computers that are on the same network? (Not visiting the same sites).

 

yes, depending on how it spreads and how secure your computer is

 

Unfortunately it definately will! Don't let him use the network!

 

Do you know what kind of virus it is? The term is sadly becoming outdated and abused. Your typical worm will open up network connections and try to spread. Trojans spread mainly via websites and e-mail, tricking users into executing them. A large portion of malware these days is associated with adware and spyware, but again, many cannot be installed without user intervention.

Also, many malware infections that do spread over a network use known vulnerabilities to do so, i.e. the Blaster worm. If you identify the malware and ensure that your systems are patched against it, then it can't do any harm. Within-network threats can be mitigated by software firewalls and router firewalls (which is why people need to keep their damn Windows Firewall turned on).
http://en.wikipedia.org/wiki/Blaster_worm