Hi w2jo - Welcome to w7forums
Sooner or later any virus program will miss catching a virus. Might as well not use a virus program at all If you are going to turn your back when it misses one. Because eventually they all miss one.
Here is an article on your login issue -
Automatic Login
I usually disable the guest login and delete all other accounts. If there is only one account, the login screen should not show during bootup. However if you have created a password for the account, the login screen will still show.