Accidentally changed my only Administrator account to Guest

Question

As the title suggests, I accidentally changed my only admin account to guest today. The account is also my Microsoft account, and I don't have any other accounts on my computer. So I ended up with only a guest account and can't use my laptop to its full potential. Since I'm not the admin anymore, I can't simply do a recovery or create a new admin account. I'm really desperate. What should I do in such case?

I don't want any "hacking" solutions, since the laptop is mine and I'd like to solve this problem in a proper way.

Thanks

EDIT: Eventually, I solved the problem by reinstalling the system.

Answer 1

Do this:

• Create Bootable USB Flash Drive
• Open a Command Prompt at Boot
• Enable Built-in Elevated Administrator Account
• Boot and login as the Built-in Administrator
• Run Control Panel > User Accounts and make your account into administrator again.
• Disable the Built-in Administrator account, for security.