LavaSoft offers RegHance, a very powerful inexpensive registry editor. There is a shareware full-feature version available but its worth registering it. Quoting from the site:

RegHance is designed to give you better overview capabilities and greater control, from building multiple lists of important keys to easier navigation. You can comment and save large numbers of keys to disk with just a few clicks of your mouse. RegHance is compatible with Windows 9x/ME/NT4.0, Windows 2000 and Windows XP. Not only does RegHance include a powerful hexadecimal editor that allows the user to read and write binary data to and from disk, it also includes advanced search and book marking capabilities. RegHance supports:

• Multiple-result searching
• Deleting and manipulation of registry keys
• Switching between horizontal and vertical views
• Native keyboard shortcuts to enhance productivity
• Search results can be:
• Converted to bookmarks
• Commented and saved to disk
• Exported as a text file