In the past some ranchers mentioned some problems when installing the practice exam software containing the mock exams. You'll find these topics here (on Mac OS X), here (on Windows 8) and here (on Windows 8.1). All these topics give a working solution for its problem.
But tonight I installed the practice exams myself and I used a much easier and simpler approach than listed in these threads. And I thought I should share this tip for everyone who might face problems while installing this software. Just 2 steps (and you don't need to use/tweak/alter the setup.msi file at all):
download and install the latest version of Adobe AIR from this link
double click on the JavaExams.air file and finish the wizard
That's all folks! Now you can enjoy the exam software. Happy studying!