I have no idea what happened! No Norton product on PC?

I bought the Norton Internet Security 2011 software for 3 computers.  I see it on my Startup Menu, in the taskbar and also have a shortcut icon on my desktop.  For some time, I've been unable to click the taskbar icon and tonight when I tried to do an update from the site, iti said that  I have no Norton product installed on my PC.  How is this possible?  

 

If I need to uninstall and reinstall, is reinstallation possible without the actual disk?  (Without paying again, of course!)  

 

TIA.