Accounts :: Disabling Login Screen - Can't Download Programs?

I just got Windows 8 and tried disabling the log-in screen. I went into "netplwiz" now I seem to have lost my administrative powers.

I can't download programs or access the "user accounts" tab in the control panel. Every time I try to do something that would require admin powers, I get a "user account control" prompt that tells me that if I, "want to allow the following programs to make changes to this computer," that I need to enter an administrator password and then click yes.

But there is no text box to enter a password and the "yes" button is grayed out. My only option is to hit "no" or "show details."

When I go into "PC Settings" and the "users" tab, it says that "there are no other users on this PC" and "Sign in as an administrator to add users to this PC." But how do I do that?

I've tried going into the "run" operation and entered "net user administrator /active:yes" command, but nothing happens. I also tried entering "msconfig" but I ran into the same problem of not having admin powers to do that. I tried starting in safe mode by jamming shift and F8 but that didn't work either.