Are you sure that these files has something to do with Norton antivirus.

My virus patterns for Norton antivirus has the size of about 5 MB, ver 5.0 to 7.5

You have four files at 3000MB, that is 12 GigaBytes????

What version of Norton antivirus are you using?

Even a server version should be ashamed to use the kind of space your desktops are using

Have you made some sort of export of the installation routines to all desktops?