Quote: "So...is it possible to make games in Java?"
possible and sensible are two very different words
nah i'm just kidding, Java is a cool little language for developing games of all ilks. Just don't expect close to the performance of C++, you have to keep projects smaller and leaner because it is an interpretive language - even if you compile most of the source into java binary you still need some execution code for looping and such which is where you loose the speed.
sniff around the mobile phone games scene, you'll pickup some very good tips
Quote: "How can I revert back to DirectX 8? "
if you setup a restore point you should be fine... if not the only way to revert is reinstall windows
well there is one other way but if you do it wrong you might loose your Windows installation anyways.
what graphics card and windows do you have? - please don't say 98 or ME cause you might as well just reinstall
DirectX9.0x notoriously hate the Win9x OSs (god knows why) tends to only happen with Via based montherboards too, which just adds to the mystery really. %)