'sqlplus' is not recognized as an internal or external command,
operable program or batch file.
Windows Server 2016 Datacenter
1. Check the PATH variable. Make sure your ORACLE_HOME\bin is correctly there. Also check your ORACLE_HOME.
How to check that, simply type on a cmd:
2. then setup:
or directly edit Environment Variables, added below command at path:
3. Restart Server
4. Re-check, okay