Windows Vista security problems?

I'm having trouble with my windows security on my Vista laptop. The Win 7 Security 2011 is unregistered. I have a Norton account ready to be set up, but the win 7 security thing won't let me get on the Internet. it says every website I try to go on may pose a threat to security, thus I can't download Norton. the windows security is going crazy trying to sell me the full version, so wha can I do or how can I get it to stop