I just did resolve this issue today! You might like to try this.

    SQL> create spfile from pfile='E:\app\<UID_W_INST_ORCL>\product\11.2.0\dbhome_1\database\INITatsm.ORA';

Then, 

    SQL> Startup

This will help you for sure. The only thing that you need is `init.ora` file.