Just wondering if the new vista os will be fully legal with upgrades and all?

Im using an HP notebook, usually, internet explorer is used as the main web browser. But I would like to download safari (which is intended for Mac). Would there be any problems if i have both?

I have a good security system on my own personal computer but a friend just got his computer and doesn't have an anti-virus. Can someone recommend the best free online anti-virus he can use for his personal computer? Thanks.