Server2012 lost admin privileges

Question

I've lost all administrative privileges on the server2012 platform. I'm not sure how this happened, but I am unable to open the Dashboard, unable to open the registry, and also unable to make changes to the registry via the powershell program. I am (or was) an admin on the server, but not sure what happened now.

Any thoughts on how to fix this? I can't even open the C: Drive.

Answer 1

Sounds like the OS is now badly broken for some reason. If you have no backups then it sounds like you may have to clean install it. Another option is to start a case here with product support.
https://support.serviceshub.microsoft.com/supportforbusiness

--please don't forget to Accept as answer if the reply is helpful--

Answer 2

I'll post the whoami /groups to see if it sheds any light, otherwise, i'll follow your guidance DSPatrick. Thank you!

Answer 3

"Group used for deny only"

because the whoami /groups was not run with elevated credentials.

--please don't forget to Accept as answer if the reply is helpful--

Answer 4

Thank you DSPatrick. I'll jump on that product support.

Answer 5

Is it possible to launch into safe mode and perform any possible actions?