Expired Norton AntiVirus to Norton Internet Security 2012 installation problems

I have had Norton antivirus running on my computer for a couple years but I let it expire recently.  I purchased Norton Internet Security 2012 from a store yesterday and went to install it only to find out my dvd drive is not working.  I tried to enter my new  norton internet security product key on my expired norton antivirus and a message appeared stating the product key was incorrect.  I really don't want to get my dvd drive replaced because the computer is 5 years old and not worth the expense.  thanks for the help