ORA-01031: insufficient privileges while connecting with sys as sysdba
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.