Can you give someone a computer virus if your computer has one already?

[Dunbar Pappy ÏŸÏŸ]

From Norton Safe Web; http://safeweb.norton.comsafety
Worms
A worm is another type of malicious code, or malware, that focuses primarily on spreading to other vulnerable computer systems. It typically spreads by sending out copies of itself to other computers, either via email, instant messages, or some other service. See the Malware Topic Center for more detailed information.