DevOps, CI/CD and Automation

I have oracle installed a client machine, linking to the server. When i sign into the server using SQL+ this works fine. However when i try and edit any ODBC driver connections in windows-control panel i get an error telling me that the networking components were not found. Also when i try to open the application that runs with oracle i get two similar errors.
The error boxes are as follows :-
little: Microsoft ODBC for oracle
Message:The Oracle(tm) client and networking components were not found. These components are supplied by oracle corporation and are part of the oracle version 7.3 (or greater) client installation.
You are unable to use this driver until these components have been installed.

2.Title: Database error
Message: IM004:[Microsoft][ODBC driver manager] Drivers SQLAllocHandle on SQL_HANDLE_ENV failed.

This is strange because i have the connection in SQL plus to the same server and the other client machines i look after are working fine.
Right before the crash the machine had Nortan antivirus 7.61 and a Disk Defrag on C:

To remedy this i have un-installed and re-installed oracle client several times with no look.

Any help would be greatly appreciated.

I have no further information about the Defrag of C: as our team did not run this, it was the IT support team we use.

Thanks in advance

Dave