Problem With Norton Internet Security 2004

My Dell 8300 came with a trial version of Norton Internet Security system which worked very well for about two months. Then I paid for a 1 year license. I ran Zone Alarm (free version) concurrently without incident. Then I made the mistake of upgrading Zone Alarm to Version 5. That was a BIG mistake. Zone Alarm V5 is very buggy (don't download it!). Now Norton Internet Security won't work, and keeps me from using the internet. I've run Norton without Zone Alarm and without the Win XP ICF firewall system, and it still blocks me. Not only that, after it causes all internet activity to halt, when I exit Netscape, then re-enter it, Netscape can't find my profile, so it wants me to start from scratch entering all my preferences and setting up mail, etc. Doing a restart makes everything work again . . . at least Netscape finds my profile. When I try to access a URL, everything halts, and I get the single word message "Stopped" in the message area. I have no idea what issues the message. It seems as though the modem stops working. When I do a reatart I get all kinds of messages saying that it can't close down various programs. It's a real mess. Anyone have an idea of what's happening?