2010 to 2011 automatic upgrade made dial-up internet useless

Using Norton Antivirus 2010 (17.8.0.5) on Windows XP

I'm on dial-up.  DSL, Cable and satellite (hills in the way) are not available.

A few months ago I experienced extremely slow internet.  Most websites were inaccessible.

 

Also noticed my net connection showed intense activity, even with no programs running.  

NAV and spyware scans were clean.  My ISP suggested I install a protocol analyzer to show where the mystery data was coming from.  

 

It showed the activity was all from  
/downloads/CLT/NAV/US/2011/18.1/ESD/NAV-UPGRADE-ESD-NoDefs-18-1-0-37-EN.exe

Somehow, my Norton 2010 decided to upgrade to 2011 without any prompting.

I'm happy with NAV 2010's current features.  I did not ask to upgrade to Norton 2011.    This unwanted upgrade has been killing my internet connection.  How can I stop the 2011 upgrade?  

Or...

If I manually download NAV-UPGRADE-ESD-NoDefs-18-1-0-37-EN.exe and ran it from my hard drive, would it upgrade to NAV 2011 and restore my internet?  (It's a 32MB file, so it would take about 3-4 hours.  I can do that overnight.)


Thanks for your help,


Mr. Broken Dial-Up user