This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
You still have an OutputStream to the file open. That means that Windows disallows renaming, deleting, etc. You can't delete or rename a file in Java unless all streams etc to it are closed. Also, the file to rename to cannot exist yet.