Norton Anti Virus

every time I try and open my Anti Virus it shuts down with with Norton Closed unexpectadly why is thsi?

According to me reinstallion of NAV on same machine is called addtional installion. For more information you can make a conversation with  "Antivirus Service" team of your antivirus.

I have a 3 licence version of Nortons Anti Virus with the tool installed on 3 PCs.   I need to reformat the HDD on one of these PCs and reinstall all of the software including Windows XP.  Can you tell me the process that I need to follow regarding the reinstallation of NAV as I am worried that I will get to the NAV install point and will be informed that the tool is already installed on 3 PCs.

Regards

Mike