For several years, I use the Norton Internet Security on Windows XP, Windows Vista and now Windows. 7 The establishment and installation of the upgrade is no problem. If you are already registered with Symantec (what to do automatically after the first installation), so you can upgrade and install it directly on a new PC, if you have previously purchased the full version (I had to do so because of PC change for defects on the old PC). So no need to first install the old full version, then upgrade.
The suite is easy to use, but loaded the system quite like everyone else. But it is in the "green" range.
I strongly recommend this "boxed" upgrade, it is considerably cheaper than the online Abboverlängerung at Symantec.
If you switch from another security suite, so you have to pre-install the old necessarily. The upgrade setup also points out and this can now even automatically.