I've installed Oracle client 12.2, and TOAD 13.1.1 on Windows 10 computer
Initially I removed the oracle home and followed this.
- delete the 12.2 client
- make sure there is no trace of any oracle client on hard drive, system path, or registry - specifically HKLM\SOFTWARE\ORACLE. you can just delete that node after deinstall. Also check HTML\SOFTWARE\Wow6432Node\ORACLE for good measure)
Reinstall oracle client
This didn't work after 4 attempts.