ORA-01031: insufficient privileges while connecting with sys as sysdba I installed Oracle database 10g as an administrator on a windows 10 machine, it worked fine, but when i try to connect sys as sysdba it gives me the error:

ORA-01031: insufficient privileges


I checked sqlnet.ora file and if SQLNET.AUTHENTICATION_SERVICES is NTS and it is:

SQLNET.AUTHENTICATION_SERVICES= (NTS)
NAMES.DIRECTORY_PATH= (TNSNAMES, EZCONNECT)


I added the user to the ORA_DBA group and i checked with:

c:\Oracle&gt;echo %username%


and

c:\Oracle&gt;NET LOCALGROUP ORA_DBA


and the user is in the group.

I don't know what else i should do, anything will be helpful.
Are you connecting as

 sys as sysdba


or   

 / as sysdba


?  

If you are using the first option, is it prompting you for a password, and are you entering the password for the user?  Did you create a local Windows user account as the user, not the user id used to install the software?  Oracle recommends a user with administrators group install the software, and a local Windows user be defined for the sys and system accounts.