Most of the XP registry packages online are for purchase. You might try any of several "trial" packages to see if you like them. They might help. I did find a "TweakNow Registry Cleaner Standard" that is free for non-commercial use. It works pretty good for me, it may or may not be sophisticated enough for your use. Everynow and then I still find a need to use the manual "regedit" function on my machine. BUT - be extremely careful if you do this!
If you are suffering from a corrupt registry that does not let you boot into windows, MS has a reg repair util for 2000/2000 Server that works on XP too. You need the 6 XP start-up disks, and the reg repair util (cant remember the exact name....search MS site for it). The util gets installed onto the last disk of the 6 disk set (should create the set before downloading the util), so instead of starting the install of WinXP, it does a reg repair. This saved my butt when the software hive took a dump on my Terminal Server. ~Rich