I have installed Oracle 12c R2 on my local Windows 10 (64 Bit) machine. For the installation I choose only to install the software.

After the installation I have used the tool that comes with the installation to create databases. After the first database was created and started I was able to connect to it without any problems.

But after I created a second database and restarted the machine only the newly created database was started.

The first database is not started on boot and I cannot start it using sqlplus. I get the error

SQL> startup
ORA-01078: failure in processing system parameters
LRM-00109: Parameterdatei 'D:\ORACLE\PRODUCT\12.2.0\DBHOME_1\DATABASE\INITDBNAME.ORA' konnte nicht ge┐ffnet werden

The said file does in fact not exist. But such a file does also not exist for the other database. The directory contains a SPFILE<DBNAME>.ORA though for both databases. As far as I know oracle uses this pattern SPFILE<DBNAME>.ORA when starting the database. If cant find said file it goes on to use INIT<DBNAME>.ORA.

I have created a INITDBNAME.ORA file and added the content:

SPFILE = 'D:\SPFILEDBNAME.ORA'

and tryed to start the database using startup pfile = 'D:\INITDBNAME.ORA' but the result was a

ORA-00205: Fehler beim Identifizieren der Kontrolldatei

error. Also confusing was that if the pfile was inside the Oracle Directory the command failed saying it cannot access the file.

EDIT After I have deleted both instances, rebooted and created both instances again I can currently access them both.

When I try to login to the first instance I get the following error:

ERROR:
ORA-01116: Fehler beim Íffnen der Datenbankdatei 5
ORA-01110: Datendatei 5:
'D:\ORACLE\ORADATA\NEMETRIS\DATAFILE\O1_MF_UNDOTBS1_DPKMRD6L_.DBF'
ORA-27041: Datei kann nicht ge÷ffnet werden
OSD-04002: Datei kann nicht ge÷ffnet werden
O/S-Error: (OS 5) Zugriff verweigert