Norton 360 not downloading

I purchased Norton 360 once my Norton Internet Security trial expired. I've tried to complete all of the steps in downloading Norton 360 but it continually pops up with an error message asking me to uninstall other Norton and Symantec products.

 

When I follow the steps to uninstall my Symantec End Point product, my computer asks for an uninstall password. I have no knowledge of what this password could be or why this is the only program needing an uninstall password.

 

Help!