Installation of Oracle 12c under Windows freezes

Symptoms: Installing Oracle 12c (12.1) under Windows 7 (x64) platform freezes aroud 68~69 percent when updating windows registry step.

Cause: The Oracle installation for Windows platform when unzipped it creates two separated directories. During the installation the installer switches the directories between those two:

• winx64_12102_database_1of2, and
• winx64_12102_database_2of2.

And cant find some files on the second directory (maybe a bug). The ongoing installation process might freezes around 68 and 69 percent and the log shows the last messages such as this:

INFO: updating registry key ‘HKEY_LOCAL_MACHINE/SOFTWARE/ORACLE/KEY_OraDB12Home1’
INFO: updating registry key ‘HKEY_LOCAL_MACHINE/SOFTWARE/ORACLE/KEY_OraDB12Home1’

Solution: Copy/move the whole content of the directory "database" from the folder "database_2of2" into the "database_1of2". Thus, the default directoy created by the unzip process (database_1of2) will have the full content to complete the installation without swiching directories.

Getting error ORA-12557 on Windows environment with multiple installations

Symptoms: Your Windows environment has more than one ORACLE_HOME and it is presenting error such as ORA-12557 TNS:protocol adapter not loadable.

Cause: The error happens on Windows environment and it has to do with PATH and ORACLE_HOME variable.

Solution: You can unset the ORACLE_HOME (better remove the variable instead of just unset via command prompt) or you can change the order of values on PATH variable, putting the ORACLE_HOME\bin at the end of the string. Reboot the machine and try again to connect on the database.