In 45 days my current Norton Antivirus 2012 expires. I'm "sitting" on a brand new three PC, AV 2011 CD that I purchased on sale. As it comes with a Product Key, is there a means to just enter the new key? If not, since the version I'm now using is 2012, I assume I'd have to uninstall it first then run the 2011 CD and then update it to 2012. Is that correct? Thank you!