After installing Oracle and opening Command Prompt, I typed in sqlplus "/as sysdba" and got an error message ERROR: ORA-01031: insufficient privileges and then it asks me to enter the user-name. I'm using my own personal computer and although the name given after C:\Users\ is not called "Administrator", it's my username when I used to log in to this computer and since I'm the only one using the computer I'm assuming it's the same as "Administrator" and when I opened account settings it says administrator under my account name.
Microsoft Windows [Version 10.0.17134.228] (c) 2018 Microsoft Corporation. All rights reserved. C:\Users\linus>sqlplus "/as sysdba" SQL*Plus: Release 18.104.22.168.0 Production on Mon Aug 20 10:56:53 2018 Copyright (c) 1982, 2010, Oracle. All rights reserved. ERROR: ORA-01031: insufficient privileges Enter user-name:
What might be the cause of this and what can I do to solve it? Thanks!