While the exact cause of this error is not known, it is worth checking if you have fulfilled all the system requirements for Java. If you are using a Windows system ...

<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: ...

Yesterday we noted Apple's release of Java Update 1.4.2 Update 1, as well as a reader report that a Java-based site that previously didn't work under OS X worked after installing the update.