This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
I believe you'll be able to access registry values that were written by Java programs relatively easily. I read that to access the entire registry, you'll need to interface with an external C/C++ program which will have to read and provide it to you. I believe this is because the windows registry is an operating system specific feature, and Java on its own won't let you do much that ties down code to specific operating systems.