Como apagar os vestígios de javac?

Ao rodar o comando 'javac Programa', o prompt retorna o erro:

C:\java-codigo>java Programa
Error: A JNI error has occurred, please check your installation and try again
Exception in thread "main" java.lang.UnsupportedClassVersionError: Programa has been compiled by a more recent version of the Java Runtime (class file version 55.0), this version of the Java Runtime only recognizes class file versions up to 52.0

1- Já desinstalei o Java (JDK e JRE) do meu computador; 2- Mesmo sem o Java instalado, ao rodar o comando 'javac', o prompt retorna as mensagens que indicam que o javac continua no computador;

C:\java-codigo>java -version java version "1.8.0_271"

C:\java-codigo>javac -version javac 1.8.0_271