183 days remaining but service has expired

I have Norton360 on both my desktop (win7) & laptop (vista) computers.  I use the laptop infrequently; mostly when I travel, as I will be doing in a few days.  I'm accessing this forum from my desktop computer because my laptop has a Norton problem as described below.

This morning was the 1st time to use my laptop in about a month (32 days, I think Norton said).  I clicked the N360 icon in taskbar.  "Security" (in red) showed At Risk, etc.  I clicked Norton Live update . . . "Service has expired".  "Account" shows 183 days remaining (same as my desktop).

Help!!  I'm panicking!  How do I fix this?