TNS_ADMIN = C:\ORANT\NET80\ADMIN
If you must proceed, you have three main options: using a virtual machine, performing a manual registry "migration," or attempting a compatibility-mode installation. Option 1: Virtual Machine (Recommended) This is the most stable method. Oracle Forums : Install virtualization software like Oracle VM VirtualBox
Extract the downloaded Oracle Developer Suite 6i package ( devsuite_6i_2004.zip ) to a directory, e.g., C:\devsuite_6i .