When I open up PuTTy, it says "login as". What is supposed to be entered?
Thanks in advance,
your username on the remote machine. probably not "root" since the account should be locked for remoteaccess.
depending on your linux distribution you set up an account during installation. use that one. otherwise you can add an user from commandline/gui. but again it depends on your linux distribution.
The user name you want to login as... After that it will try and pub/priv key pairs it has (if support), other authentication (like kerberos), then password auth.