RegDefrag: Defrag & Optimize Windows Registry
RegDefrag is a free utility by Quicksys, that defrags your Windows Registry by removing gaps, fragments and wasted space. It even optimizes your registry to help improve performance and boost access to it. This is a very small (approx. 1 MB), light and easy-to-use application. It is also safe to use because it does not modify any registry entries.
Quicksys RegDefrag is compatible with Windows 2000, XP and Vista.