If you use your system enough to generate a rat's nest of a Registry, you no doubt have the qualifications to use this logically laid-out toolkit. It's as easy and thorough as following a flowchart. The Help file contains loads of information to aid you in interpreting your bootlog results too. The trial version is good for 10 days of use, then you must register. Visual Basic 5.0 runtimes are required, with the VB5 files you may need available at the product's download page.
Support is offered during the trial period, and to registered users.
RegRepair 2000 is well worth a try.