[Hollywood]

Many alternatives...

Ununistall the software completely, restart and make sure you don't have anything loading on startup via registry. A god way to check is to use msconfig for registry noobs, if you don't have msconfig.exe download it from Microsoft's site and put it in your System/System32 folder. Any registry key linking Norton should be removed, but as long as you don't see anything in startup you should be ok.

Reinstall it with your key, or just find one online, most Norton products don't have unique keys. Now configure the software to not block the programs you use. I am assumning you are using a firewall via Norton Internet Security.

Cliffs
1) use msconfig
2) remove statup processes
3) if you know what you are doing, use regedit to clean out keys and links
ex HKEY_LOCAL_MACHINE->SOFTWARE->MICROSOFT->WINDOWS->CURRENT VERSION->RUN
4) uninstall/reinstall
5) configure