Unable to upgrade to 2012 from 2012 nis

Yesterday i renewed my subscription to Norton using NIS 2011, i have tried to upgrad to 2012 using the new version check, after going through the various messages to run and continue etc i get an error message saying:

 

A problem has occured that needs your attention

 

This product is not compatable with this computers operating system, you must have one of the following, then it goes on to list them

 

Im on Vista and 2011 has worked fine so why will this not work?

 

Thanks