I'm not a 'Proper' administrator

I am the only user on my laptop. I accepted the Toshiba settings when I
bought the machine, but I realise that there are a number of features that
are disabled that (as an administrator) I should be able to use. for
example:

1. Windows Defender will show me the details of start-up programs but not
allow me to remove/enable/disable anything (the buttons are
greyed-out/disabled).

2. There are some folders (e.g. in my internet favourites) which are
read-only and when I switch read-only off, it ignores what I've done - they
remain read-only.

thanks

M