sotware

Hi! currently i m using norton as antivirus sotware but i m satisfied with its scans. can you tell me the best antivirus software to use. or it should be better that norton.

Well I just wanna know about licenses that people give out with there softwarez. I am currently developing an OS and want to get COPYRIGHT for it.... I also wanna know that what is a trademark? do i also need to have trademark to give license with my software... Bassically what I need...