UAC yes button missing

[bvb40170]

No matter what I try to do on my laptop (Windows 10 Pro) I run up against a UAC pop up which only gives me the option to click No.
I suspect I am no longer the admin on my own laptop and, again, no matter what I try including regedit I cannot become an Admin again.
I should add that I have tried
https://www.windows10forums.com/threads/re-install-w10-and-keep-your-files-app-data-intact.15825/
and when trying to complete the pc reset it asks to sign in as admin and password. The only option is No which takes me back to the start again. How do I get a yes button on this UAC pop up?
Help, please!

 

[bvb40170]

Hi! Whenever I try to do something on my laptop I get the UAC pop up Access is Denied. It appears that I am no longer an Admin on my own laptop. I have tried several methods of changing my account from Local to Admin with no success. Each time I am taken back to the Access denied pop up so I'm going round in circles. Looks like you can't be an Admin without already being an Admin!
I tried the regedit method but again same result. Access denied. I cannot even download a program because I need to sign in as Admin and use the password.
The pop up only has a No button so I can't enter anything
I also tried https://www.windows10forums.com/threads/re-install-w10-and-keep-your-files-app-data-intact.15825/ but this only took me back to the same pop up.
My laptop was recently rebuilt and I suspect with a digital key. Could this be the problem?
Any help appreciated. Thanks.