If you get this error message while installing the Metaboli Player, you probably have not installed Java or it might not have been installed correctly.

Make sure the program is installed by checking your Windows control panel. If you find Java, please right-click on it then choose Uninstall.

See here how to do this according to your OS:

Windows 7

1. From the Start menu, select Control Panel.
2. In Large or Small icon view, click Programs and Features. If you're using Category view, under "Programs", click Uninstall a program.
3. Select the program you want to remove, and click Uninstall. Alternatively, right-click the program and select Uninstall.

Windows Vista

1. From the Start menu, select Control Panel.
2. In Classic View, double-click Programs and Features. In Control Panel Home view, under "Programs", click Uninstall a program.
3. Select the program you want to remove, and click Uninstall. Alternatively, right-click the program and select Uninstall.

Windows XP in default XP view

1. From the Start Menu, select Control Panel.
2. Click the Add or Remove Programs icon.
3. Select the program you wish to remove and click Remove.
4.  

Once uninstalled Java, please restart your machine, then download and install Java as explained in this article:

Help - Games-On-Demand \ C. Technical problems \ II. Installing and operating the Metaboli Player \ 02. Installation of the Metaboli Player

Than come back to Metaboli, login and start the installation process again from here.