Windows Defender blocking startup programs..

> Hi there,
>
> I was just wondering how I would go about unblocking certain programs I
> trust. Windows blocks the program at startup, and gives me a popup saying
> run
> blocked program. I have checked Windows Defender and all that says next to
> the program is "Not yet classified".
>
> Is there like a trust list that I can put this program into or something
> like that so I don't get that annoying popup at startup and just actually
> get
> this program to run at startup?
>
> Any help will be muchly appreciated.