Solved Lost administrator privileges

I was frustrated that Windows 8 required me to input my password every time, but after searching online, I found out a way to automatically sign in whenever I start up my computer. Later on, I decided to change my Microsoft account to a local account (can't remember why), and then I changed back. Once I changed back, I had to do the password thing again.

Now, though, my account is set to a "Guest" account, and whenever I'm asked to allow something as an administrator (which tends to happen a lot), I'm not allowed to click "Yes", with "No" being the only option. This is a major issue that needs to be fixed, and any help would be appreciated.

Can you try to do a System Restore to the point where you were admin still?

That's kind of a last resort answer; I'd rather not have to go there.