How to sign in as Administrator? Or change to Administrator level?

Hi,

I have a Dell XPS 15Z and have been getting bluescreens so I'm trying to run Debugger.

I get to the bit where I select open minidump file and I get a message saying I need to be a system administrator., which I am. But when I look at User accounts, I am a standard user and it won't let me switch to an Administrator.

How do I get past this point? Or, how do I check and see if another super Administrator account was set up when the computer was originally set up?

Thanks,

Richard