I'm hoping someone can help me.

My firewall reports the following:
"Application Hijacking has been detected
The application: C:\Program Files\Common Files\Symantec Shared\NMain.exe try to launch another application: C:\Program Files\Norton AntiVirus\NAVW32.EXE"

I have gotten ~700 messages (and counting) from my virus scanner that it has found and deleted the virus JAVA_BYTEVER.A

What is going on, and how do I stop it?

Do you have the most recent windows updates and the most recent Norton updates? Get those. I also highly recommend Mozilla's Firefox browser instead of Internet Explorer. Go to www.mozilla.org for a free download.