I might be a hopeless programmer?

wrote a small application memorycards for kids (images music etc.)
compiled from MAC through netbeans. The program works fine on mac by just 2xclicking on the jar. But on a pc of a friend he gets the following message


Notice that tries to find a file jar.clas on the path D:\MemoryCards\.

Modalidad de receptor registrada

Invocando método JS: document

Invocando método JS: URL

Referencia a cargador de clases: sun.plugin.ClassLoaderInfo@17a4989, contador de referencia=1

Cargando miniaplicación...

Inicializando miniaplicación...

Iniciando miniaplicación...

cargar: clase MemoryCards.jar no encontrada.

java.lang.ClassNotFoundException: MemoryCards.jar

at sun.applet.AppletClassLoader.findClass(Unknown Source)

at java.lang.ClassLoader.loadClass(Unknown Source)

at sun.applet.AppletClassLoader.loadClass(Unknown Source)

at java.lang.ClassLoader.loadClass(Unknown Source)

at sun.applet.AppletClassLoader.loadCode(Unknown Source)

at sun.applet.AppletPanel.createApplet(Unknown Source)

at sun.plugin.AppletViewer.createApplet(Unknown Source)

at sun.applet.AppletPanel.runLoader(Unknown Source)

at sun.applet.AppletPanel.run(Unknown Source)

at java.lang.Thread.run(Unknown Source)

Caused by: java.io.FileNotFoundException: D:\MemoryCards\jar.class (El sistema no puede hallar la ruta especificada)

at java.io.FileInputStream.open(Native Method)

at java.io.FileInputStream.<init>(Unknown Source)

at java.io.FileInputStream.<init>(Unknown Source)

at sun.net.http://www.protocol.file.FileURLConn...onnect(Unknown Source)

at sun.net.http://www.protocol.file.FileURLConn...Stream(Unknown Source)

at sun.applet.AppletClassLoader.getBytes(Unknown Source)

at sun.applet.AppletClassLoader.access$100(Unknown Source)

at sun.applet.AppletClassLoader$1.run(Unknown Source)

at java.security.AccessController.doPrivileged(Native Method)

... 10 more

Excepción: java.lang.ClassNotFoundException: MemoryCards.jar