Windows 10: Regaining Administrator Access

Thanks. Unfortunately, I can't seem to download anything because I no longer have permission. I'll try to set up a bootable drive from my Mac and plug it in once it's ready.

Wish I knew how I ended up in this mess...

 

This sounds to me like an infection of some sort. I suggest you download Kyhi's bootable PE rescue media and run a Malwarebytes scan on your system. Update the virus definitions and be sure to select Custom Scan and select the box to scan for rootkits (it's unchecked by default).
Windows 10 Recovery Tools - Bootable Rescue Disk - Windows 10 Forums

 

You can format the USB to FAT32 on the MAC, download Kyhi's PE ISO onto the MAC, mount the ISO to see the files in it, and copy the files over to the USB stick. Then boot the Windows system to the USB stick and run Malwarebytes.

 

Thanks a bunch, everyone! I'll try to get the PE rescue media first. If that doesn't work I'll have to boot back up from the USB.

 

Or burn the ISO file to CD using the built-in Disk Utility on your Mac.
As far as I know, just copy the contents of the ISO file to USB and it might doesn't work.

 

It appears I have fixed the problem.

I accessed command prompt and typed "shutdown /r /o". From there, I went into safe mode, and was able to restore administrative access to my main account. Everything seems to more or less work.

 

Good news. *Smile I hope everything's working properly now for you. If you're satisfied, please go ahead and mark the thread as solved. Cheers!