Norton and Internet help needed

Hi I have used your site before for a Spyware problem and it was a great halp, so I was hoping oyu'd be able to help me with a couple of other problems I am having. 1. Norton Anti-Virus keeps giving me a message (every single day) telling me that my virus defintions are out of date. I have updated them since, but the message won't go away. 2. When downloading files from the internet, they often just stop, for no apparent reason. Why could this be? 3. Can't download Windows Updates anymore because it says my Windows is genuine, though I have downloading updates from there before and they worked fine. (Recently got the WebUpdate feature and after a while it didn't seem to be downloading anything, so I decided to check the website for updates, but couldn't) Thanks for any help you can offer Lauren