PC setting back to factory setting

hi,

 

i sent my PC for repair and this meant all the applications, systems, etc are wiped out, that is, back to factory setting.

 

my last payment for the norton antivirus is Nov 2011 and i am not sure if the subscription is still valid and what do i have to do to re-install the software.

 

any help will be appreciated.

 

thanks

carol