I still think the best way to get rid of the index.dat files, is to look into it a bit deeper. What is the root of the problem? The answer of course is Windows itself. So the best course of action would be to solve the problem at the source, and in this case, that would be to get rid of windows. Completely. Then you will have solved the problem without adding even more headache to the problem, ie- adding more software, registry hacks, etc...