The reason for the 'oraoledb. oracle.1 'provider is not registered on the local machine

There are three possible reasons for this situation.

1. Is the machine with Oracle installed NTFS? If yes, grant all bin permissions under \ ora81 to all users.
(Otherwise, this error will be reported due to no permission to access the directory in the B/S structure)

2. If the database server is oracle816. Find the sqlnet. ora file under ora81 \ Network \ ADMIN on the server and
Change sqlnet. authentication_services = (CNT)
Sqlnet. authentication_services = (none)
(This will cause some machines to report an error in driver initialization failure, which occurs once in oracleclient)

3. If none of the above issues are resolved. Check whether the registration in the registry is actually lost. (The possibility is relatively small, Windows is safer)
Regsvr32 .. \ ORACLE_HOME \ bin \ oraoledb. dll
You can try again by reinstalling the client.