Help please!!

Thanks javap for starting this thread. I really do need to fix  java setting in my computer. When i open my university page for registration which runs with the help of java software. Its lower half window is completely dark like the lower boundary extended upto half of the java window and i can't see any link within the darker region. But for some other program the java window is fine. I would be more than happy is some experts could help me to fix it.