Solution : https://service.sap.com/sap/support/notes/178871 (SAP Service marketplace login required)
Key words : 
registry tree hkey_local_machine\software\oracle, oracle network configuration files oracle7, additional key words reinstallation, oracle fail safe configurations, oracle release-dependent notes, inconsistent oracle installation/configuration, registry key home0, hkey_local_machine\software\oracle, registry variable dba_authorization, additional configuration files
Related Notes : 
       
| 144011 | Current patch set 7.3.4.X | 
| 127395 | Current patch set for Oracle Rel. 8.0.5 | 
| 123951 | Installation Oracle 8.0.4.2 patch for Windows NT | 
| 99311 | Current patch set 8.0.4.X | 
| 92052 | Current Oracle patch set for version 7.3.3 |