Windows has 2 classes of userids. You are using a "standard". It has basic access to Windows. When you install applications that modify the Windows you need to give the application "Administrator" access through the "UAC" prompt you were given.
This article tells you how to enable a built in administrator account
https://www.ghacks.net/2014/11/12/how-to-enable...
Then when you get prompted for admin you give it the id and password.