Installing NIS 2011 from disc on top of NIS 2010

Hello:-,

A friend of mine wants me to install NIS 2011 on his computer via disc.
He's running XP SP3 with NIS2010.

The reason for this is that he's using a very slow dial up internet connection that would take all day ( you have to stay there and watch it or the service will kick you offline if you don't indicate that you're still using it by pushing a button) and he can also have a copy of the program on CD to use if has a problem at some time in the future.

So, my questions are:

1. Can you install 2011 from disc on top of the 2010 ( just as you do on your normal upgrade via an internet download) without any problems?

2. Would it be best to use the new keycode with the new disc, or just put in his old one which has about a week left on it?  Or does this even matter?

 Opinions on the path of least foreseeable problems would be appreciated.

Thanks in advance.