<tl;dr> To fix the Eclipse “No Java virtual machine was found” error, simply edit the eclipse-inst.ini file and add the -vm flag, which points it to the java utility in the JDK bin directory: ...

There is java.exe and javaw.exe but typing in "javaw first.java" opens up a popup titled "Java Virtual Machine Launcher" with the text "Could not find the main class. Program will exit.".