Question: how to check if jdk is installed from command prompt?
Answer: POSSIBLE SOLUTIONS: 1) Start a CMD shell (click "Start" button ⇒ "run..." ⇒ enter "cmd") and issue a path command: prompt> path PATH=....... 2) Check if it includes your JDK's "bin" directory. For example, suppose that your JDK is installed in "c:\program files\java\jdk-13.0.