Hi,
I think Norton Products are amazing. They are so improved since 2009 came out.
Thought, I have problems with 2010 on my 64-bit machine. After installing Norton, Explorer.exe crashes a LOT and my windows never show up. After uninstalling Norton, problem is gone! I will switch to Microsoft Security Essentials until this problem is fixed. Thanks!
Orgional thread: http://www.sevenforums.com/crashes-debugging/45522-horrible-windows-7-problem-explorer-exe-has-stopped-2.html
Also, Windows is up-to-date and Norton has been updated using "Live Update" Many times!