So I have a client who is deploying multiple versions of oracle in a cross-platform environment. They store their TNS Names file on a network resource. The users will be accessing via Windows 8.1. There will be both 32 and 64 bit versions of 12c. The client wants to be able to use the TNS_ADMIN environment variable to resolve for TNS names and basically wants this to be a permanent setting for each user who logs on the workstation. I have read numerous articles some say set under HKLM under the environment key some say create it under HKLM and software. Some say HKCU which would only work for the currently logged in user. Any assistance with this would be appreciated.