I have made a simple game that I want to convert into a runnable jar so I can show others and launch it without Eclipse. In Eclipse I: Right clicked on Project Export Java Exectuable Jar File Launch Configuration: CTB (1) - Click The Block It made a jar with a MANIFEST.MF containing: Manifest-Version: 1.0 Class-Path: . Main-Class: uk.co.robertmerriman.ctb.main.CTB This was all extracted to my desktop in Click-The-Block.jar When I double click, nothing happens. When I type "java -jar Click-The-Block.jar" into CMD, I get the following error: Error: Unable to access jarfile Click-The-Block.jar.