I got this error when trying to run MATLAB 6 R12.

“Failure Loading Desktop Class”

The first result in Google didn’t help. But Solution 1-1881O did.

I’m running Windows XP on a Dell Dimension 4600 with a 2.4 GHz Pentium 4. With a similar (P4-based) setup, you may get the same error. To fix it, simply download and run this patch: JREpatch.exe.

Make sure MATLAB is closed when you run it. The first time I did, I was running MATLAB (although it wasn’t working) – and some files couldn’t be overwritten. After running the patch, MATLAB worked like a charm.