Could not initialize class gnu.io.RXTXCommDriver...

OS: Windows 7 Ultimate (64 bit)

History: Have been using IDE Version 16. Yesterday upgraded to Version 22. Everything worked fine. Loaded and compiled the rather large sketch I have been working on, uploaded to the Mega board, ran. No problems.

This morning I rebooted the machine and when I load the sketch I get the following error (in the first window that opens when you start the IDE):

java.lang.NoClassDefFoundError: Could not initialize class gnu.io.RXTXCommDriver thrown while loading gnu.io.RXTXCommDriver

When I try to compile the sketch I get a Compile Error and garbage in the lower window.

Everything works just fine still in Version 16.

I suspect I need to change versions of Java (I have the java folder in V16 renamed so it won't be used). Am I right and if so how do I do that?

OK, uninstalled Java and installed latest version (V6 Update 23). No help.

Got it working. But frustrated.

All my design projects are on my J: drive -- including all my Arduino IDE installs. If I install V22 on my J: drive it doesn't work. However if I install it on my C: (boot drive) its working fine. Disk check of J: reveals no problems.

Frustrating. I hate computers & OSs sometimes...