Version update Nav 2010-2011

hello, i want to buy NAV 2010 with 3 license, what i want to know is are there any possible issues during update of the program -not defenitions and is it possible the same update to become impossible on some strange way?

 

When you update this way do you get 100% same product as Norton 2011? or there are some difference ?

 

Thanks!

 

P.S. What if i run trial version on the same pc do i need to uninstall it or?